050 - Wind, fire and a surprise

Transcript

WEBVTT 00:00:00.288 --> 00:00:03.919 <v Guillermo Rein>Welcome to episode 50 of fire science show. 00:00:03.943 --> 00:00:07.932 <v Guillermo Rein>My name is Guillermo Rein and I am taking over the podcast today. 00:00:08.099 --> 00:00:10.769 <v Guillermo Rein>This is an important episode for three reasons. 00:00:10.829 --> 00:00:13.778 <v Guillermo Rein>One is because it's number 50 it's a number to celebrate. 00:00:13.919 --> 00:00:16.239 <v Guillermo Rein>It's a long series of episodes. 00:00:16.359 --> 00:00:16.928 <v Guillermo Rein>It's really good. 00:00:17.469 --> 00:00:21.338 <v Guillermo Rein>Second is because Wojciech is not going to interview anyone today. 00:00:21.579 --> 00:00:27.129 <v Guillermo Rein>That's unusual in a podcast that he created, that he has been doing every week interviewing people is because be. 00:00:27.939 --> 00:00:29.498 <v Guillermo Rein>Who is going to interview someone. 00:00:29.588 --> 00:00:32.448 <v Guillermo Rein>And the third surprise is that I am going to interview Wojciech. 00:00:32.829 --> 00:00:39.881 <v Guillermo Rein>So he is going to be talking to you, but instead of, extracting information from others and making them talk, it is going to be the other way around. 00:00:39.911 --> 00:00:41.292 <v Guillermo Rein>He is going to be talking to us. 00:00:41.322 --> 00:00:44.606 <v Guillermo Rein>He's going to be sharing his lessons, his experiences, and his messages. 00:00:45.130 --> 00:00:49.604 <v Guillermo Rein>So this is, Uh, an episode that is important in a podcast, a series that is important. 00:00:49.865 --> 00:00:59.878 <v Guillermo Rein>Wojciech tells me that he's super happy to know that about 25,000 downloads of the episodes have happened on average, 500 downloads per episode. 00:00:59.878 --> 00:01:02.728 <v Guillermo Rein>He's really, really happy about this and keeps growing. 00:01:02.758 --> 00:01:12.125 <v Guillermo Rein>And I just wish him the best and that this keeps in this direction and hopefully the interview of the creator um, helps to cement farther the growth of the series. 00:01:12.454 --> 00:01:15.531 <v Guillermo Rein>So Wojciech is going to talk us about a specific topic. 00:01:15.531 --> 00:01:19.581 <v Guillermo Rein>He is is, as you will listen to in the interview, he's a Renaissance person. 00:01:19.590 --> 00:01:20.995 <v Guillermo Rein>he, he does everything. 00:01:21.415 --> 00:01:23.125 <v Guillermo Rein>And when he does something, he does it really well. 00:01:23.125 --> 00:01:34.960 <v Guillermo Rein>Like I said, um, so all the topics I decided to ask him about one thing that he's very well known because he got awards and really good papers, which is in the modeling computational modeling of fire and wind. 00:01:35.721 --> 00:01:37.956 <v Guillermo Rein>The two of them have massive interactions as well. 00:01:37.965 --> 00:01:38.676 <v Guillermo Rein>You will tell you. 00:01:38.945 --> 00:01:43.686 <v Guillermo Rein>And when they interact, they make the problem of modeling more interesting and more challenging. 00:01:43.715 --> 00:01:54.516 <v Guillermo Rein>He is one of the messages he has for the community, especially the younger ones is that people should not be put off by the complexity of combining wind and fire that they should endure. 00:01:54.546 --> 00:01:56.286 <v Guillermo Rein>That difficulty is challenging. 00:01:56.316 --> 00:01:57.745 <v Guillermo Rein>He's telling us, be aware. 00:01:57.756 --> 00:02:01.805 <v Guillermo Rein>He's telling you, he knows that he's telling you, but it's also rewarding and it is important. 00:02:01.805 --> 00:02:04.475 <v Guillermo Rein>And as an engineer, he himself can tell us about. 00:02:05.361 --> 00:02:12.604 <v Guillermo Rein>Solutions to safety that he has found by not shying in a way from wind, but by embracing when and couple it with, with fire. 00:02:13.025 --> 00:02:16.534 <v Guillermo Rein>So there is a lot to learn from Wojciech the scientists and Wojciech the engineer. 00:02:16.598 --> 00:02:18.457 <v Guillermo Rein>and just, just assess that. 00:02:18.668 --> 00:02:22.700 <v Guillermo Rein>And then I will just, let you listen to what he has to say. 00:02:46.135 --> 00:02:51.930 <v Guillermo Rein>So Wojciech I I'm delighted to be here with you. 00:02:51.930 --> 00:02:54.240 <v Guillermo Rein>I'm delighted that you are finally being interviewed. 00:02:54.240 --> 00:02:58.199 <v Guillermo Rein>You've interviewed so many people, 49 people, I think, or 48. 00:02:58.729 --> 00:03:02.750 <v Guillermo Rein>you have an incredible good taste in choosing topics and people that's. 00:03:02.900 --> 00:03:12.695 <v Guillermo Rein>I think part of the massive success of the podcast, but the most important thing is your ability to have amazing conversations with multiple different personalities. 00:03:13.228 --> 00:03:15.117 <v Guillermo Rein>And that says a lot about you. 00:03:15.448 --> 00:03:16.168 <v Guillermo Rein>We adore you. 00:03:16.168 --> 00:03:21.207 <v Guillermo Rein>We need you, and we, we want your show to keep going for a long time. 00:03:21.268 --> 00:03:26.974 <v Guillermo Rein>Um, so I'm very happy to give a grain of sand and to be the one interviewing you today, 00:03:26.990 --> 00:03:27.139 <v Wojciech Wegrzynski>Yeah. 00:03:27.169 --> 00:03:27.610 <v Wojciech Wegrzynski>Thank you. 00:03:27.759 --> 00:03:28.780 <v Wojciech Wegrzynski>Thank you so much, man. 00:03:28.780 --> 00:03:29.500 <v Wojciech Wegrzynski>It's so hard. 00:03:30.009 --> 00:03:32.349 <v Wojciech Wegrzynski>I mean, this is the same seat, but it feels much different. 00:03:33.159 --> 00:03:35.770 <v Wojciech Wegrzynski>I'm very happy and thanks for all the kind words. 00:03:35.770 --> 00:03:42.599 <v Wojciech Wegrzynski>And I'm happy to find finally be able to share some of my own research at the ITB that, that makes me very happy. 00:03:42.960 --> 00:03:43.919 <v Wojciech Wegrzynski>So what did you pick. 00:03:45.185 --> 00:03:45.604 <v Guillermo Rein>Excellent. 00:03:45.634 --> 00:03:48.724 <v Guillermo Rein>So you could be interviewed about many different topics. 00:03:48.754 --> 00:03:50.435 <v Guillermo Rein>You are a Renaissance, man. 00:03:50.435 --> 00:03:56.574 <v Guillermo Rein>You, you have multiple interests, sewing the podcast, but you have multiple contributions in different topics. 00:03:56.574 --> 00:04:01.375 <v Guillermo Rein>I think that definitely is going to be modeling, although you are very good with experiments. 00:04:02.479 --> 00:04:13.240 <v Guillermo Rein>And within modeling, obviously fire, because it's a topic off of the podcast, but you, you have these really interesting and early, contribution on fire and wind modeling the two of them. 00:04:13.270 --> 00:04:17.769 <v Guillermo Rein>So it's computational fluid mechanics, not just a fire, but of wind, which is an interface. 00:04:17.769 --> 00:04:17.980 <v Guillermo Rein>Right. 00:04:17.980 --> 00:04:21.189 <v Guillermo Rein>So can you tell us a little bit of how you end up working on this 00:04:21.504 --> 00:04:21.745 <v Wojciech Wegrzynski>yeah. 00:04:21.774 --> 00:04:22.285 <v Wojciech Wegrzynski>Thanks man. 00:04:22.314 --> 00:04:22.555 <v Wojciech Wegrzynski>Thanks. 00:04:22.555 --> 00:04:23.454 <v Wojciech Wegrzynski>Thanks for picking this. 00:04:23.454 --> 00:04:25.134 <v Wojciech Wegrzynski>It's it's very near to my heart. 00:04:25.187 --> 00:04:28.187 <v Wojciech Wegrzynski>it started somewhere in like 2012, 13. 00:04:28.697 --> 00:04:30.648 <v Wojciech Wegrzynski>I was not really a scientist back then. 00:04:30.648 --> 00:04:45.324 <v Wojciech Wegrzynski>I was a consultant and we were doing modeling for four buildings and, we ended up having this, project in the middle of the Warsaw, uh, Hala Koszyki Center we we've celebrated the first, uh Obora in, in that particular building. 00:04:45.894 --> 00:04:50.295 <v Wojciech Wegrzynski>, And it was an old, historical, uh, shopping mall inside of the town. 00:04:50.295 --> 00:04:51.675 <v Wojciech Wegrzynski>That was to be refurbished. 00:04:52.245 --> 00:05:03.586 <v Wojciech Wegrzynski>And because it was a historical mall, to remove the smoke from it, the only choice you had were rows of windows that were underneath the roof, that was the only, the only way you could extract smoke from there. 00:05:03.750 --> 00:05:04.620 <v Guillermo Rein>I remember seeing those. 00:05:04.874 --> 00:05:05.386 <v Wojciech Wegrzynski>Yeah. 00:05:05.415 --> 00:05:11.386 <v Wojciech Wegrzynski>And because, uh, these windows are known for being very inefficient for smoke removal in wind conditions. 00:05:11.935 --> 00:05:19.555 <v Wojciech Wegrzynski>, my colleagues Grzegorz Krajewski and Grzegorz Sztarbala have started doing modeling for the building to establish. 00:05:19.737 --> 00:05:22.228 <v Wojciech Wegrzynski>How efficient the ventilation is in it, you know? 00:05:22.257 --> 00:05:28.701 <v Wojciech Wegrzynski>And, Grzegorz Sztarbala was doing his PhD on, um, the wind influence on tunnels. 00:05:28.701 --> 00:05:29.721 <v Wojciech Wegrzynski>It was very interesting. 00:05:29.721 --> 00:05:31.401 <v Wojciech Wegrzynski>So they've applied a lot of knowledge. 00:05:31.790 --> 00:05:35.911 <v Wojciech Wegrzynski>They got so far, they ended up modeling, , a big part of the city. 00:05:35.911 --> 00:05:39.750 <v Wojciech Wegrzynski>This is where I came into the project because I helped them build the models and run them. 00:05:40.480 --> 00:05:53.100 <v Wojciech Wegrzynski>And it was like so interesting, such an interesting case study where you'd actually modeled the wins to truly , answer the question, will it interfere with the smoke control or not? 00:05:53.550 --> 00:06:02.740 <v Wojciech Wegrzynski>And I think that it was very surprising to me to find, such a rich interaction inside was not a simple, yes, no, it doesn't interfere. 00:06:02.740 --> 00:06:03.341 <v Wojciech Wegrzynski>It does not. 00:06:03.821 --> 00:06:10.081 <v Wojciech Wegrzynski>You know, you could see how the flows from different streets would create a completely different, performance of the system. 00:06:11.146 --> 00:06:11.985 <v Wojciech Wegrzynski>Just fascinating. 00:06:11.985 --> 00:06:15.766 <v Wojciech Wegrzynski>And we've published many studies about that building, that are available online. 00:06:15.766 --> 00:06:18.555 <v Wojciech Wegrzynski>I think it was a very nice case study. 00:06:18.555 --> 00:06:21.750 <v Wojciech Wegrzynski>And, since then I started playing with it. 00:06:21.750 --> 00:06:23.639 <v Wojciech Wegrzynski>You know, I've built some models. 00:06:23.639 --> 00:06:30.420 <v Wojciech Wegrzynski>I I've made some buildings, started pushing, wind on them, rotating them, seeing what happens. 00:06:30.420 --> 00:06:33.509 <v Wojciech Wegrzynski>And the answer was never, never simple. 00:06:34.079 --> 00:06:47.699 <v Wojciech Wegrzynski>And then fast forward few years, and we go into some conferences, we talk with people about the projects and because we had no idea how to deal with this wind projects, we had to use best practices of wind engineering. 00:06:48.310 --> 00:06:51.480 <v Wojciech Wegrzynski>And for us, it was kind of obvious you did like. 00:06:52.334 --> 00:07:07.754 <v Wojciech Wegrzynski>And then you meet fire people and sorry for calling you guys fight people, but then you meet fire people and they drink it completely other way in, in what seems to when engineers, there's a wrong way and you're getting into discussions and you realize that it's not that simple. 00:07:07.754 --> 00:07:32.658 <v Wojciech Wegrzynski>It's not, such an easy thing to actually perform these studies together in, in a way that is scientifically justified, that you control the uncertainty that you actually model wind and, this is when we've decided that maybe because there as there are no good practice guidelines, I thought it might be a good idea to write ones and yeah, two, three years, but it was worth it it's. 00:07:32.658 --> 00:07:42.947 <v Wojciech Wegrzynski>So ended up in, in fire technology has ended up being an, a quite well-received paper , and that, that was the entrance to the beautiful world of wind and fire. 00:07:43.216 --> 00:07:45.286 <v Guillermo Rein>thank you for mentioning the paper. 00:07:45.286 --> 00:07:50.206 <v Guillermo Rein>I have it in front of me is a two-part paper is, is a absolutely beautiful paper. 00:07:50.290 --> 00:07:56.286 <v Guillermo Rein>I just really, I read it again for the interview on, and again, I, I was like, oh wow. 00:07:56.795 --> 00:07:58.956 <v Guillermo Rein>It is as good as I remember it even better. 00:07:59.646 --> 00:08:00.545 <v Guillermo Rein>It's part two. 00:08:00.545 --> 00:08:00.846 <v Guillermo Rein>Right? 00:08:00.846 --> 00:08:02.165 <v Guillermo Rein>So it has part one and part two. 00:08:02.165 --> 00:08:03.846 <v Guillermo Rein>And actually you got a best paper award. 00:08:03.971 --> 00:08:04.300 <v Wojciech Wegrzynski>Yeah. 00:08:04.331 --> 00:08:04.651 <v Wojciech Wegrzynski>Thanks. 00:08:04.721 --> 00:08:05.201 <v Wojciech Wegrzynski>Thank you. 00:08:05.315 --> 00:08:07.266 <v Guillermo Rein>do you want to tell us a little bit about that experience? 00:08:07.300 --> 00:08:09.088 <v Wojciech Wegrzynski>Oh, it I was so surprised. 00:08:09.088 --> 00:08:17.295 <v Wojciech Wegrzynski>I, I mean, as a young scientist, you know, there are many of these awards where you, battle with other young scientists and it's, it's fun. 00:08:17.295 --> 00:08:24.295 <v Wojciech Wegrzynski>Uh, it's fun to get these awards, but a Bigglestone award, you battle with, dinosaurs at the best of the best. 00:08:24.564 --> 00:08:26.944 <v Wojciech Wegrzynski>So I was never thinking of that. 00:08:27.014 --> 00:08:31.894 <v Wojciech Wegrzynski>This contribution could actually become the best paper of the year. 00:08:32.495 --> 00:08:33.988 <v Wojciech Wegrzynski>And, it was fantastic. 00:08:33.988 --> 00:08:35.187 <v Wojciech Wegrzynski>It opened the whole. 00:08:36.173 --> 00:08:44.470 <v Wojciech Wegrzynski>World of possibilities for us, because we suddenly could say that the work is important to the community that it is, received, by the community. 00:08:44.470 --> 00:08:46.720 <v Wojciech Wegrzynski>And we had to that it is important, you know? 00:08:47.049 --> 00:09:00.256 <v Wojciech Wegrzynski>So for a young scientist, thing like that, it's it's life-changing man, I think it's, uh, like you mentioned, the ERC was life-changing for you, maybe not on the same scale, but you know, that, that, that's, that's a similar thing. 00:09:00.256 --> 00:09:12.039 <v Wojciech Wegrzynski>it's truly changes, not who you are because we're doing the same things, with the same scrutiny, same tools, , but suddenly many, many more doors open than there were open before. 00:09:12.039 --> 00:09:16.480 <v Wojciech Wegrzynski>So I really appreciate that, that total board of five technology for choosing. 00:09:17.075 --> 00:09:20.375 <v Wojciech Wegrzynski>These, this paper as the best paper of that year. 00:09:20.375 --> 00:09:24.845 <v Wojciech Wegrzynski>And truly there was so much work put into that, that paper. 00:09:25.504 --> 00:09:26.945 <v Wojciech Wegrzynski>And it was a little long ish. 00:09:27.274 --> 00:09:29.134 <v Wojciech Wegrzynski>Sorry for that. 00:09:29.735 --> 00:09:34.921 <v Guillermo Rein>Well, that's, that's why it's two parts right now, but congratulations, I think this is a success story. 00:09:35.225 --> 00:09:44.914 <v Guillermo Rein>you may actually want to write suddenly you could offer a talk, to young academics and young researchers about the success story of a topic that you push forward. 00:09:44.914 --> 00:09:47.794 <v Guillermo Rein>A topic that probably at the beginning, people were saying, it's not needed. 00:09:48.125 --> 00:09:51.245 <v Guillermo Rein>You don't have to write about this book and then you did it. 00:09:51.274 --> 00:09:56.884 <v Guillermo Rein>And then you end up with a beautiful paper and an award and an interview in a famous book test. 00:09:58.534 --> 00:10:02.674 <v Guillermo Rein>So part one of this paper is a literature review and I really liked. 00:10:03.575 --> 00:10:06.455 <v Guillermo Rein>I literally, you literally scan the horizon. 00:10:06.455 --> 00:10:14.105 <v Guillermo Rein>I realized if you go high altitude and then you start going lower altitude into any details, can you tell us a little bit about the structure of why do you choose this? 00:10:14.164 --> 00:10:16.835 <v Guillermo Rein>You have six, parts in the literature review. 00:10:16.865 --> 00:10:17.585 <v Guillermo Rein>Can you tell 00:10:17.639 --> 00:10:37.113 <v Wojciech Wegrzynski>we, we go all the way from, um, modeling, the flows inside the buildings, we're modeling the ventilators and the let's say the interference phase between the building and the exterior we go into tunnels, uh, because that's an interesting twist in the, in the problem. 00:10:37.743 --> 00:10:45.480 <v Wojciech Wegrzynski>And in the end, we, we move, outside the building into wildfires and, uh, urban interface areas. 00:10:45.480 --> 00:10:55.105 <v Wojciech Wegrzynski>And then just, dispersion of the smoke in the urban scale, because wind is a phenomenon that, interferes with fire at every scale. 00:10:55.466 --> 00:11:01.676 <v Wojciech Wegrzynski>And I thought, I always, you know, I come from the ventilator business. 00:11:02.125 --> 00:11:04.946 <v Wojciech Wegrzynski>So, so my interface is the ventilator. 00:11:05.669 --> 00:11:10.395 <v Wojciech Wegrzynski>the smoke removal devices in the buildings, I got the dampers and everything you used to remove the smoke. 00:11:10.395 --> 00:11:13.546 <v Wojciech Wegrzynski>This is my, my core business or use. 00:11:13.546 --> 00:11:18.466 <v Wojciech Wegrzynski>Now it's wider, but for us, wind is just a resistance. 00:11:18.466 --> 00:11:23.929 <v Wojciech Wegrzynski>You know, the, the damper, subject to event has worse performance than when it's not subject to wins. 00:11:24.332 --> 00:11:31.202 <v Wojciech Wegrzynski>And after my studies starting with the Hala Koszyki and then other studies, I immediately realized this is bullshit. 00:11:31.623 --> 00:11:32.822 <v Wojciech Wegrzynski>This doesn't make sense. 00:11:32.822 --> 00:11:33.153 <v Wojciech Wegrzynski>Okay. 00:11:33.153 --> 00:11:41.163 <v Wojciech Wegrzynski>If you just consider a single ventilator, it makes sense the wind is resistance, but when you place that vent on. 00:11:42.677 --> 00:11:45.498 <v Wojciech Wegrzynski>And the roof has beautiful pressure pattern on it. 00:11:45.918 --> 00:11:47.207 <v Wojciech Wegrzynski>Some part is negative. 00:11:47.207 --> 00:11:48.408 <v Wojciech Wegrzynski>Some part is positive. 00:11:48.798 --> 00:11:50.238 <v Wojciech Wegrzynski>It's so complex. 00:11:50.357 --> 00:12:05.418 <v Wojciech Wegrzynski>When you put the winds on the building facade where it can push air, or it can block air from coming out of the building, this ventilator will work in a completely different way and it will give completely different barometers of its performance. 00:12:05.687 --> 00:12:13.008 <v Wojciech Wegrzynski>So narrowing down to the single thing being a vent made, we understood the problem completely wrong. 00:12:13.038 --> 00:12:17.957 <v Wojciech Wegrzynski>We understood it just for the vent, not for the fire safety and the same goes for a building. 00:12:17.957 --> 00:12:27.768 <v Wojciech Wegrzynski>If you just model the building in isolation, standing there in an empty space, or just put some inlets around it, say it has this dynamic pressure. 00:12:27.798 --> 00:12:29.408 <v Wojciech Wegrzynski>This is the wind that acts on it. 00:12:29.702 --> 00:12:30.841 <v Wojciech Wegrzynski>What you do is you write. 00:12:31.816 --> 00:12:37.125 <v Wojciech Wegrzynski>Essentially exposing the building to a certain value of pressure, but not wind when there's a complex phenomenon. 00:12:37.125 --> 00:12:46.125 <v Wojciech Wegrzynski>I always joke that, you know, imagine if we took the complex phenomenon as a fire and just replaced it with a simple time temperature relation, how stupid would that be? 00:12:49.495 --> 00:13:02.442 <v Wojciech Wegrzynski>And that's what we, as a fire scientist tried to do with, uh, with winds we don't, appreciate the complexity of the phenomenon and with this complexity comes diversity of outcomes of, the wind ethics. 00:13:02.773 --> 00:13:08.802 <v Wojciech Wegrzynski>So this is why we thought in the review paper, we can not just tell people the story about the buildings. 00:13:09.013 --> 00:13:12.373 <v Wojciech Wegrzynski>We cannot just tell the story about, um, the ventilators. 00:13:12.732 --> 00:13:16.062 <v Wojciech Wegrzynski>We need to try and find out what. 00:13:16.436 --> 00:13:19.414 <v Wojciech Wegrzynski>The fire community at whole has learned about wind. 00:13:19.445 --> 00:13:26.375 <v Wojciech Wegrzynski>And, and there were like, there were reviews by Pitts from NIST about a war fires, which was amazing. 00:13:26.404 --> 00:13:30.274 <v Wojciech Wegrzynski>It was fantastic resource on wind and fire interaction. 00:13:30.274 --> 00:13:41.934 <v Wojciech Wegrzynski>On the city scale, we found brilliant papers about firebrands aerodynamics, they're so rich in knowledge about when we went into fire whirls that's this, this is another fascinating phenomenon. 00:13:42.144 --> 00:13:46.465 <v Wojciech Wegrzynski>So we thought, okay, if the, if we want to give it the justice, if we want this. 00:13:47.399 --> 00:13:54.389 <v Wojciech Wegrzynski>The fire community to be exposed to how wind is done and how one should include wind in their analysis. 00:13:54.389 --> 00:14:03.929 <v Wojciech Wegrzynski>We need to give a broad view on the subject because it is much more rich than most people would think. 00:14:03.929 --> 00:14:13.470 <v Wojciech Wegrzynski>And I hope that I can do it in like three pages, but no, it was a home, a whole 80,000 character paper about, about this. 00:14:13.470 --> 00:14:16.919 <v Wojciech Wegrzynski>And we still have not probably captured all, all the knowledge that was there. 00:14:17.265 --> 00:14:19.620 <v Guillermo Rein>Thank you for talking about all the ventilators and the buildings. 00:14:20.417 --> 00:14:21.736 <v Guillermo Rein>you touched many beautiful problems. 00:14:21.736 --> 00:14:27.616 <v Guillermo Rein>One of them that I invite you to say more about now, if you want is tunnels, you look into when and tunnels and fire. 00:14:27.697 --> 00:14:33.154 <v Wojciech Wegrzynski>Oh, yeah, we just recently had, commissioned the tunnel in Warsaw, very big road tunnel. 00:14:33.597 --> 00:14:37.077 <v Wojciech Wegrzynski>we've spent almost half year that in the tunnel. 00:14:37.498 --> 00:14:44.125 <v Wojciech Wegrzynski>And one of the main question was how does wind affect, the flows inside the tunnel, you know? 00:14:44.125 --> 00:14:52.528 <v Wojciech Wegrzynski>And, it sounds like a simple question, but, to answer that you need to answer, what do you mean by winds? 00:14:52.528 --> 00:14:54.327 <v Wojciech Wegrzynski>You know, that that's a fundamental question. 00:14:54.327 --> 00:14:56.097 <v Wojciech Wegrzynski>What is wind like? 00:14:56.128 --> 00:14:59.128 <v Wojciech Wegrzynski>A wind has a velocity. 00:14:59.226 --> 00:15:02.937 <v Wojciech Wegrzynski>it has gusts because it's not just a constant flow of air. 00:15:02.937 --> 00:15:10.779 <v Wojciech Wegrzynski>It's, uh, it's huge vortices that move around your, region you sometimes have high velocity, somethings have flow velocities. 00:15:11.169 --> 00:15:17.950 <v Wojciech Wegrzynski>So it's very complicated, but first you have velocity, so there's a certain probability associated with different velocities. 00:15:17.980 --> 00:15:21.820 <v Wojciech Wegrzynski>Like, should we design a tunnel for a hurricane? 00:15:21.879 --> 00:15:23.019 <v Wojciech Wegrzynski>Which don't happen in Poland? 00:15:23.139 --> 00:15:24.669 <v Wojciech Wegrzynski>No, it doesn't happen. 00:15:25.000 --> 00:15:30.399 <v Wojciech Wegrzynski>So you need to figure out for what wind velocity would you like to design your tunnel? 00:15:30.789 --> 00:15:37.659 <v Wojciech Wegrzynski>And the action of each of these velocities will be different, but two to make it even more complicated when has the direction component to it? 00:15:37.921 --> 00:15:44.523 <v Guillermo Rein>when you, one thing, when you, you mentioned wind and tunnels, you really mean the wind outside the tunnel and how it alters the inside. 00:15:44.523 --> 00:15:46.952 <v Guillermo Rein>But, but the inside itself is not wind. 00:15:46.952 --> 00:15:47.163 <v Guillermo Rein>Right? 00:15:47.163 --> 00:15:47.913 <v Guillermo Rein>That's what, that's 00:15:47.947 --> 00:15:59.758 <v Wojciech Wegrzynski>Inside you have some flow that is induced by the wind, but the wind action outside, it creates this, some of the, of the pressure, the dynamic pressure of the wind, creates the flow 00:15:59.817 --> 00:16:02.368 <v Guillermo Rein>Yeah, but yeah, because it changes the boundary 00:16:02.607 --> 00:16:03.807 <v Wojciech Wegrzynski>exactly it. 00:16:03.988 --> 00:16:14.878 <v Guillermo Rein>And, and this is something is, is fascinating because not many people actually look into this many people look into the modeling of the flows inside the tunnel, but very few people look into the effect of a flow mechanics 00:16:14.898 --> 00:16:24.498 <v Wojciech Wegrzynski>and I tell you, this is the issue we've, um, we also felt into, because we've designed the system in 2015, for this tunnel. 00:16:24.528 --> 00:16:38.898 <v Wojciech Wegrzynski>And we went with the best knowledge of the time, and we didn't really consider that much as a factor or not as such a dynamic factor as, as now, um, in this tunnel we be that transversal ventilation system. 00:16:38.898 --> 00:16:44.148 <v Wojciech Wegrzynski>We really wanted to have low velocity in the tunnel around 1.5 meters per second. 00:16:44.868 --> 00:16:46.337 <v Wojciech Wegrzynski>That was our design goal. 00:16:46.727 --> 00:16:50.868 <v Wojciech Wegrzynski>And the wind could create a flow of four or five meters in the tunnel easily on its own. 00:16:51.288 --> 00:17:02.207 <v Wojciech Wegrzynski>We had array of jet funds in the tunnel that could be used to stop the winds, but if we start all of them together and there is no wind, then the Jetsons will create this overwhelming force. 00:17:02.207 --> 00:17:06.587 <v Wojciech Wegrzynski>So we needed to find a balance between the wind and the jet fans in the tunnel. 00:17:07.157 --> 00:17:20.607 <v Wojciech Wegrzynski>And that led to design of 688 different scenarios of operation of the tunnel for different velocities of the wind outside and different wind direction angles. 00:17:20.788 --> 00:17:30.807 <v Wojciech Wegrzynski>And only then we could say, okay, no matter what wind is outside the system, if it triggers in the correct scenario, it will stop the winds to do more or less the level we needed. 00:17:31.377 --> 00:17:33.137 <v Wojciech Wegrzynski>And so the, this. 00:17:33.537 --> 00:17:38.037 <v Wojciech Wegrzynski>Probably the most difficult wind fire interaction I've done in my career. 00:17:38.037 --> 00:17:39.386 <v Wojciech Wegrzynski>And this was not modeling. 00:17:39.386 --> 00:17:42.596 <v Wojciech Wegrzynski>We had the tunnel, we had the measurements, we had the weather station. 00:17:42.896 --> 00:17:44.696 <v Wojciech Wegrzynski>We could I'll tell you a story. 00:17:44.757 --> 00:17:46.946 <v Wojciech Wegrzynski>I was, it was like Saturday. 00:17:47.156 --> 00:17:48.807 <v It's like 9>00 PM. 00:17:48.807 --> 00:17:53.376 <v It's like 9>The children are going to sleep and I am dressing up, packing up. 00:17:53.467 --> 00:17:55.386 <v It's like 9>My wife is asking me, well, where are you going? 00:17:55.386 --> 00:18:01.567 <v It's like 9>And I'm like, I need to go to the tunnel, but why I need to measure the velocity in the tunnel. 00:18:02.767 --> 00:18:03.696 <v It's like 9>Cannot someone else do it. 00:18:03.696 --> 00:18:04.416 <v It's like 9>No I've called them. 00:18:04.416 --> 00:18:05.317 <v It's like 9>No one is there. 00:18:05.317 --> 00:18:10.446 <v It's like 9>I need to go there to measure, but, but why do you need, there is very rare winds occurring now. 00:18:10.717 --> 00:18:12.096 <v It's like 9>And my wife is like, w w what? 00:18:12.096 --> 00:18:12.767 <v It's like 9>what wind is occuring?. 00:18:12.787 --> 00:18:13.116 <v It's like 9>I'm sorry. 00:18:13.446 --> 00:18:19.176 <v It's like 9>It was like, because we had very, very rare southern wind with a velocity above six beats per second. 00:18:19.176 --> 00:18:24.247 <v It's like 9>And I really needed to go to the tunnel to get this data point because I missed it. 00:18:24.277 --> 00:18:26.606 <v It's like 9>I, we never had that when we really missed it. 00:18:26.616 --> 00:18:28.836 <v It's like 9>And I, I had, I packed my anemometer. 00:18:28.836 --> 00:18:29.946 <v It's like 9>I run into the tunnel. 00:18:29.946 --> 00:18:30.594 <v It's like 9>I've measured. 00:18:30.594 --> 00:18:35.903 <v It's like 9>the thing the guys from security were looking at me like, what's he doing here in the, in nights? 00:18:36.113 --> 00:18:43.217 <v It's like 9>But I took the point and it really helped me solve the issue because we've found the missing points that connected, many other together. 00:18:43.217 --> 00:18:50.116 <v It's like 9>And we finally had this full, full circle and, and the full understanding comprehension of how winds will affect the tunnel. 00:18:50.146 --> 00:18:54.547 <v It's like 9>But yeah, when we imagine a tunnel, that's a pipe, it has to open. 00:18:55.666 --> 00:19:00.586 <v It's like 9>And we ended up with almost 700 different scenarios in each of them is completely different. 00:19:01.317 --> 00:19:07.512 <v It's like 9>And now imagine the building a skyscraper, which has endless amount of openings, the tunnel is simple. 00:19:07.512 --> 00:19:08.413 <v It's like 9>It's in the ground. 00:19:08.833 --> 00:19:22.212 <v It's like 9>The skyscraper can be 500 meters up in the troposphere escaping, escaping the lowest, atmospheric boundary layer, how complicated it is then, and in fire, how we deal with problems. 00:19:22.212 --> 00:19:24.313 <v It's like 9>We don't understand, we omit them. 00:19:24.403 --> 00:19:27.732 <v It's like 9>That that was not a choice we thought is, is viable. 00:19:27.759 --> 00:19:29.133 <v It's like 9>we wanted to understand it. 00:19:29.702 --> 00:19:38.210 <v It's like 9>We're still, still not there, but, uh, on the route and, and tunnels are a great example , of what you can learn by touching winds, especially if it's a rare wins. 00:19:39.048 --> 00:19:46.444 <v Guillermo Rein>you you're making a very good case for the importance of wind that sometimes it can help in this smoke movement and in the fire movement. 00:19:46.444 --> 00:19:47.375 <v Guillermo Rein>And sometimes he can not. 00:19:48.164 --> 00:19:54.035 <v Guillermo Rein>you're already alluding to this, but, so what do you propose as, engineer, you're near that obviously you are not proposing that is ignore. 00:19:54.125 --> 00:19:57.095 <v Guillermo Rein>As most cases have happened to date. 00:19:57.575 --> 00:20:06.015 <v Guillermo Rein>Uh, you, are you proposing to focus on the worst case scenario or proposing a probabilistic approach or, I mean, you you're mentioning multiple scenarios. 00:20:06.015 --> 00:20:14.791 <v Guillermo Rein>So tell us more about what you propose of, how an engineer can deal with this scientific, ability to study the interactions of wid smoke and 00:20:14.902 --> 00:20:20.362 <v Wojciech Wegrzynski>Yeah, this is a very good question and a very difficult one to answer. 00:20:20.761 --> 00:20:23.251 <v Wojciech Wegrzynski>obviously as, you mentioned, is, is complicated. 00:20:23.251 --> 00:20:24.721 <v Wojciech Wegrzynski>There are hundreds of scenarios. 00:20:24.902 --> 00:20:26.551 <v Wojciech Wegrzynski>I mean, even probabilistic. 00:20:27.041 --> 00:20:29.494 <v Wojciech Wegrzynski>Too expensive or most cases. 00:20:29.944 --> 00:20:34.855 <v Wojciech Wegrzynski>So it's very difficult to like capture this phenomenon together completely. 00:20:35.303 --> 00:20:43.561 <v Wojciech Wegrzynski>we are now running a, a research grant, funded by Polish NCN agency where we're somewhere around the middle of it. 00:20:43.951 --> 00:20:50.882 <v Wojciech Wegrzynski>And the goal of this grant is to solve that completely for a single building in a single location of the town. 00:20:50.882 --> 00:21:01.382 <v Wojciech Wegrzynski>We choose an open car park because this is a very interesting case study where the, where the wind can truly have the tremendous impact over the course of the fire. 00:21:01.922 --> 00:21:06.152 <v Wojciech Wegrzynski>And, it will require from what we. 00:21:06.440 --> 00:21:19.670 <v Wojciech Wegrzynski>Established at the moment, somewhere between 1000 to maybe 4,000 different scenarios to completely have like a complete view on, on different fires and winds how they interact and what are the outcomes. 00:21:20.000 --> 00:21:23.299 <v Wojciech Wegrzynski>And this is only once to be done. 00:21:23.329 --> 00:21:38.057 <v Wojciech Wegrzynski>Like we, we really want to understand the complete image, but, from previous case studies, we had case studies in which we did, uh, let's say two meters per second, five meters per second, 10 meters per second, average wind velocity. 00:21:38.807 --> 00:21:43.007 <v Wojciech Wegrzynski>And in this case studies, we found the middle one to give the worst results. 00:21:43.396 --> 00:21:47.267 <v Wojciech Wegrzynski>Like the strongest winds would actually give better results than those lowest one. 00:21:47.866 --> 00:21:48.833 <v Wojciech Wegrzynski>And that was really. 00:21:49.218 --> 00:21:53.740 <v Wojciech Wegrzynski>Surprising, you know, because suddenly, okay, so we don't have the worst wind. 00:21:53.769 --> 00:21:55.990 <v Wojciech Wegrzynski>Like this is uncomfortable for me. 00:21:56.289 --> 00:22:01.390 <v Wojciech Wegrzynski>I always thought the stronger, the worst, just pick the, the strongest reasonable wind you have. 00:22:01.390 --> 00:22:05.470 <v Wojciech Wegrzynski>And you're good, but no, this case studies shown it's not the case. 00:22:05.500 --> 00:22:06.819 <v Wojciech Wegrzynski>It's, it's, it's complicated. 00:22:07.442 --> 00:22:22.002 <v Wojciech Wegrzynski>so essentially enter a problem that that's potentially not possible to solve, but when the writing this review papers that were mentioned, we also figured out that, okay, let's go to building. 00:22:22.353 --> 00:22:28.140 <v Wojciech Wegrzynski>when does the wind affect the building a fire when it becomes its boundary condition? 00:22:28.140 --> 00:22:30.480 <v Wojciech Wegrzynski>Like you mentioned the wind becoming a boundary of the portals. 00:22:31.109 --> 00:22:31.349 <v Wojciech Wegrzynski>So. 00:22:32.201 --> 00:22:41.053 <v Wojciech Wegrzynski>Maybe we can have a cheaper way to establish in which wind scenario it is likely to be the worst boundary condition. 00:22:41.982 --> 00:22:53.143 <v Wojciech Wegrzynski>And then once we determine, this scenarios, you go into full wind and fire simulations, which are expensive because if you simulate just wind, no fire, you can run it as a steady state problem. 00:22:53.772 --> 00:22:56.761 <v Wojciech Wegrzynski>It is not as computationally expensive. 00:22:56.779 --> 00:23:01.519 <v Wojciech Wegrzynski>I can do a 20, 30, 50 simulations of just wind at the time. 00:23:01.519 --> 00:23:03.170 <v Wojciech Wegrzynski>I will do one wind and fire study. 00:23:03.470 --> 00:23:22.640 <v Wojciech Wegrzynski>So you can actually do hundreds of wind scenarios of your building that you're interested in and determine, in which scenarios you have obtained, the biggest pressure rise on the inlets or outlets when there was the highest under pressure on your events, you know, just investigate the pressure on the building. 00:23:23.555 --> 00:23:28.038 <v Wojciech Wegrzynski>In which scenarios you had the most extreme values of this, of these pressures. 00:23:28.428 --> 00:23:36.218 <v Wojciech Wegrzynski>And they usually would correspond to the scenarios in which the wind fire interaction would be the strongest in your fire case. 00:23:36.835 --> 00:23:40.835 <v Wojciech Wegrzynski>especially when you have, for example, over pressure on your exhaust vents. 00:23:40.884 --> 00:23:45.894 <v Wojciech Wegrzynski>This is when the wind will block the smoke inside the building and will not allow it to escape. 00:23:45.894 --> 00:23:47.394 <v Wojciech Wegrzynski>So this is definitely the worst case. 00:23:47.934 --> 00:24:00.714 <v Wojciech Wegrzynski>And by this, you can narrow down from hundreds of scenarios to be investigated into a number that is manageable by the engineer, and then focus on, on this particular snow. 00:24:00.724 --> 00:24:03.144 <v Wojciech Wegrzynski>This is how we solve a Hala Koszyki problem. 00:24:03.474 --> 00:24:11.891 <v Wojciech Wegrzynski>We narrowed down into the ones that are most likely to, be a problematic and then solve for them and see what happens. 00:24:12.221 --> 00:24:17.171 <v Wojciech Wegrzynski>And I think at this stage, this is probably the best, the best you can do. 00:24:17.201 --> 00:24:18.221 <v Wojciech Wegrzynski>It's not easy. 00:24:18.490 --> 00:24:21.609 <v Wojciech Wegrzynski>It is not needed for all projects, for sure. 00:24:21.647 --> 00:24:26.246 <v Wojciech Wegrzynski>but, when you need an answer, it's the best way you can find one. 00:24:26.792 --> 00:24:27.125 <v Guillermo Rein>Perfect. 00:24:27.175 --> 00:24:38.799 <v Guillermo Rein>Thank you Wojciech and you have already alluded to wildfires, but because what if ours is such an, an up-and-coming fire, phenomenon, uh, w w where there's a lot of needs for. 00:24:39.920 --> 00:24:45.599 <v Guillermo Rein>And you yourself have interview Michael Gollner and Sarah McAllister and Cathejline Stoof. 00:24:46.415 --> 00:24:53.826 <v Guillermo Rein>you in your 2018 paper, this paper that we're referring to, you actually went and review the literature of wildfires. 00:24:53.915 --> 00:24:58.536 <v Guillermo Rein>And when modeling, you want to tell us about this, that was one of the parts that I enjoy the 00:24:58.695 --> 00:24:59.056 <v Wojciech Wegrzynski>Really? 00:24:59.625 --> 00:25:00.526 <v Wojciech Wegrzynski>It makes me happy. 00:25:00.875 --> 00:25:01.256 <v Wojciech Wegrzynski>Uh, 00:25:01.715 --> 00:25:06.756 <v Guillermo Rein>you have amazingness sketch you're really good with the sketches and drawings and you have a particularly good 00:25:06.766 --> 00:25:07.155 <v Wojciech Wegrzynski>Yeah. 00:25:07.306 --> 00:25:09.165 <v Wojciech Wegrzynski>I mean, it was a four for us. 00:25:09.165 --> 00:25:15.096 <v Wojciech Wegrzynski>It was probably the most difficult one to write you know, because, , we're not a wildfire experts. 00:25:15.096 --> 00:25:21.665 <v Wojciech Wegrzynski>And, uh, we were worried that we may omit something critical for a wildfire community. 00:25:22.115 --> 00:25:34.986 <v Wojciech Wegrzynski>And in this particular, chapter w we got help from Mike Gollner and Ali Tohidi who were kind enough to refer us to some, some studies, about when the fire that has been done in that community. 00:25:35.645 --> 00:25:41.675 <v Wojciech Wegrzynski>And, um, I think it is even if you go back to Rothera mills model, when there's a factory in there, 00:25:42.523 --> 00:25:43.453 <v Guillermo Rein>one of the three most 00:25:43.499 --> 00:25:44.138 <v Wojciech Wegrzynski>Yeah, exactly. 00:25:44.138 --> 00:25:51.778 <v Wojciech Wegrzynski>I, and you don't have to be a, a fire scientist to understand that the wind influences wildfires and how they spread. 00:25:52.318 --> 00:26:01.068 <v Wojciech Wegrzynski>So definitely, , It was a parallel field to the building fire science that had its own take in fires. 00:26:01.578 --> 00:26:07.689 <v Wojciech Wegrzynski>however, I think the problem is slightly different than buildings, in, in wildfires. 00:26:08.409 --> 00:26:18.944 <v Wojciech Wegrzynski>I think, the wind you could, if you could oversimplify the case, like the wildfire case, the wildfire is like a boundary layer problem. 00:26:18.944 --> 00:26:25.095 <v Wojciech Wegrzynski>You know, that there, the, forest will be essentially a roughness boundary condition on your ground. 00:26:25.355 --> 00:26:45.575 <v Wojciech Wegrzynski>it will influence how the flow is changing in this boundary layer, but in general, it will not change the structure of the wind so much where in the, in the city, this is something that was the most scary finding of our work in cities. 00:26:46.037 --> 00:26:53.109 <v Wojciech Wegrzynski>Concept doesn't really work that well, you cannot put an isolated building and just, mimic the city with the roughness criteria. 00:26:53.109 --> 00:27:04.059 <v Wojciech Wegrzynski>And then just pretend you're doing winter because the array of, of streets in the city will create a completely individual flow path around your building. 00:27:04.509 --> 00:27:15.230 <v Wojciech Wegrzynski>In that case study that I've mentioned just before, when we found that the middle velocity was the worst one, we also found that, the building was a rectangular building and it had an opening on the, on the shorter wall. 00:27:15.230 --> 00:27:19.549 <v Wojciech Wegrzynski>So we thought, okay, if we blow directly to the door, it will be definitely the worst case. 00:27:19.819 --> 00:27:25.039 <v Wojciech Wegrzynski>And it was not the worst case was when the wind was like 45 degrees to the right. 00:27:25.579 --> 00:27:31.299 <v Wojciech Wegrzynski>And the wind was like hitting a building nearby, running around the building and hitting our door. 00:27:31.299 --> 00:27:34.960 <v Wojciech Wegrzynski>That was the worst case because of the complexity of the, of the, of the system in there. 00:27:35.920 --> 00:27:40.210 <v Wojciech Wegrzynski>Here, even though we're, we're talking about wind, this is the same thing. 00:27:40.630 --> 00:27:50.057 <v Wojciech Wegrzynski>I think the problems we face in the wildfire community faces is completely different in, in terms of, what is needed and in the wildfire community. 00:27:50.057 --> 00:27:55.364 <v Wojciech Wegrzynski>I think, what's the most beautiful thing is they truly do forecasting. 00:27:55.394 --> 00:28:01.314 <v Wojciech Wegrzynski>You know, they, they work, to forecast how fires will grow. 00:28:01.733 --> 00:28:03.384 <v Wojciech Wegrzynski>Uh, where will they go? 00:28:03.413 --> 00:28:05.213 <v Wojciech Wegrzynski>Where will the smoke go? 00:28:05.307 --> 00:28:06.297 <v Wojciech Wegrzynski>how will it spread? 00:28:06.896 --> 00:28:07.317 <v Wojciech Wegrzynski>And. 00:28:08.487 --> 00:28:10.406 <v Wojciech Wegrzynski>They do something we never do in buildings. 00:28:10.406 --> 00:28:17.426 <v Wojciech Wegrzynski>They measure the wind and try to incorporate that measurement in their forecasts, in the reduced order models. 00:28:17.426 --> 00:28:25.330 <v Wojciech Wegrzynski>And for me, this was absolutely mind blowing how beautiful these solutions can be, in our case, you have to make up the winds. 00:28:25.330 --> 00:28:27.851 <v Wojciech Wegrzynski>You know, you have to have this logarithmic wind profile. 00:28:27.851 --> 00:28:34.211 <v Wojciech Wegrzynski>You have to make up completely based on science obviously, but you make it up and here they deal with something they truly measure. 00:28:34.780 --> 00:28:43.151 <v Wojciech Wegrzynski>And it's something that you can like the closer you are to the forecast, the more, you know, the more accurate it should be. 00:28:43.201 --> 00:28:47.641 <v Guillermo Rein>You mean that because wildfire has happened on very large timescales? 00:28:47.671 --> 00:28:49.621 <v Guillermo Rein>No, they will be spreading for days. 00:28:49.990 --> 00:28:53.461 <v Guillermo Rein>You are saying that they can measure the wind profile in real time and then do a 00:28:53.546 --> 00:29:01.053 <v Wojciech Wegrzynski>They can, they can incorporate the momentary metrological data in their analysis to refine their, forecasts. 00:29:01.442 --> 00:29:10.952 <v Wojciech Wegrzynski>And for buildings, you don't have a building model readily available when the fire is ongoing not to mention metrological data. 00:29:10.952 --> 00:29:19.365 <v Wojciech Wegrzynski>So I think only for the biggest, most difficult fires, you will go into any, any sort of modeling of a fire during a fire. 00:29:19.875 --> 00:29:22.096 <v Wojciech Wegrzynski>Uh, while in wildfires, I think this. 00:29:22.448 --> 00:29:26.468 <v Wojciech Wegrzynski>A simpler model because it's not only CFD can use Eulerian and models. 00:29:26.468 --> 00:29:28.268 <v Wojciech Wegrzynski>You can use, uh, Lagrangian models. 00:29:28.688 --> 00:29:35.178 <v Wojciech Wegrzynski>There is, um, I mean, even simple Goshen dispersion or puff models are, are being used, to forecast. 00:29:35.208 --> 00:29:45.498 <v Wojciech Wegrzynski>Uh, I actually was very happy to write a chapter four on that for Brian Meacham's handboook and Margaret McNamee's is a handbook that's coming up soon. 00:29:45.708 --> 00:29:46.038 <v Wojciech Wegrzynski>Ish. 00:29:46.067 --> 00:29:52.151 <v Wojciech Wegrzynski>I hope, uh, where, where we go in depth in, how we can model this, um, wind and smoke interaction. 00:29:52.961 --> 00:29:58.050 <v Wojciech Wegrzynski>And, I think in, in welfare committee, the wind is maybe even more essential than it is for us. 00:29:58.050 --> 00:30:10.171 <v Wojciech Wegrzynski>How are I think the solution that may be even maybe a little easier than, than for us, because for us this, Specific flow paths of, city wind is, is something that can drive your fire behavior. 00:30:10.381 --> 00:30:17.820 <v Wojciech Wegrzynski>And that that's unfortunate because it makes the problem so much more complex than, than just, uh, you know, a simple boundary condition 00:30:17.934 --> 00:30:18.295 <v Guillermo Rein>Cool. 00:30:18.845 --> 00:30:19.684 <v Guillermo Rein>Think of Wojciech you are. 00:30:19.704 --> 00:30:21.085 <v Guillermo Rein>You're such a Renaissance man. 00:30:21.115 --> 00:30:23.815 <v Guillermo Rein>Confirm, um, also in the interview, 00:30:24.065 --> 00:30:26.884 <v Wojciech Wegrzynski>in the render sense you would die for forecasting weather. 00:30:26.884 --> 00:30:28.055 <v Wojciech Wegrzynski>So that's not great. 00:30:28.414 --> 00:30:30.365 <v Wojciech Wegrzynski>That's not great, you know? 00:30:31.755 --> 00:30:33.605 <v Guillermo Rein>following the structure of your paper in part. 00:30:34.227 --> 00:30:40.788 <v Guillermo Rein>you go be joined the literature review and you're going to something which is very nice and very rarely done in science. 00:30:40.788 --> 00:30:43.240 <v Guillermo Rein>You actually provide our best practice guidance. 00:30:43.795 --> 00:30:55.228 <v Guillermo Rein>this is amazing and I encourage all engineers in the field to take a look at no a leader in the topic is actually saying what he has learned and he sharing, the, lessons and the hints. 00:30:56.397 --> 00:31:03.998 <v Guillermo Rein>So in that, in part two, there are you, you literally, we could be talking about this for days, but let, let's try to make it just the podcast episode. 00:31:04.567 --> 00:31:18.877 <v Guillermo Rein>So for example, you talk about a topic that is really important in modeling and CFD is there this discretisation and do you want to tell us about the importance of discretisation in the specifics of when you are doing fires smoke? 00:31:19.593 --> 00:31:40.576 <v Wojciech Wegrzynski>Yeah, this was a huge challenge for us and, uh, my co author Tomek Lipecki, who, who, uh, uh, actually, uh, should have mentioned him in the start, because this is, this was a two man or at the, at some three men work with, with . But Tomek I guess, has done immense work on, on, on this review along me. 00:31:40.576 --> 00:31:44.026 <v Wojciech Wegrzynski>And it was a huge pleasure to work with him on this. 00:31:44.026 --> 00:31:46.546 <v Wojciech Wegrzynski>And we're still working together on wind and fire. 00:31:46.875 --> 00:31:55.066 <v Wojciech Wegrzynski>So, so high five to, to Tomek um, Thomas was a researcher who did not do any fire is a wind engineer. 00:31:55.516 --> 00:31:59.339 <v Wojciech Wegrzynski>but he did a lot of work on scaffoldings, around building. 00:32:00.049 --> 00:32:19.940 <v Wojciech Wegrzynski>And funnily in the issues in discretisation of space, when you model scaffoldings and model fire are seemingly the same because you have this tiny thing that is inside your building or around your building for him, it's a scaffolding for me is the scale at which the fire phenomenon happened. 00:32:20.630 --> 00:32:27.123 <v Wojciech Wegrzynski>So it's, it's in the centimeters, let's say, and you have wind and you can really do a centimeter mesh. 00:32:27.123 --> 00:32:33.752 <v Wojciech Wegrzynski>When you were modeling two by two kilometer, large domain in wind engineering, you would go to 15, 25 meters cells. 00:32:33.782 --> 00:32:37.742 <v Wojciech Wegrzynski>That's not very odd that you go into such a cell dimensions. 00:32:38.103 --> 00:32:42.272 <v Wojciech Wegrzynski>Whereas in fire you would like to use relatively small meshes. 00:32:42.663 --> 00:32:49.883 <v Wojciech Wegrzynski>We tend to use 10, 5, 20 centimeters, based on the star, which is not the measure of mesh quality, by the way. 00:32:50.153 --> 00:32:54.742 <v Wojciech Wegrzynski>That's I always feel horrible when I see people justify their choice by that. 00:32:54.742 --> 00:32:55.373 <v Wojciech Wegrzynski>But yeah. 00:32:56.452 --> 00:33:00.682 <v Wojciech Wegrzynski>Regardless, we use meshes incentive meters, whereas in fires you would use meters 00:33:01.083 --> 00:33:03.292 <v Guillermo Rein>you mean the same to me, the same fire where we meet. 00:33:03.643 --> 00:33:03.913 <v Wojciech Wegrzynski>yeah. 00:33:03.913 --> 00:33:04.813 <v Wojciech Wegrzynski>Centimeters in fire. 00:33:04.813 --> 00:33:11.173 <v Wojciech Wegrzynski>And whereas it would be meters in wind and you know, this tiny detail, I mean, what is the consequence of that? 00:33:11.262 --> 00:33:15.009 <v Wojciech Wegrzynski>Well, first of all, in the wind, you would run. 00:33:15.411 --> 00:33:20.015 <v Wojciech Wegrzynski>steady state simulations, like I mentioned before, or some sort of periodic simulation. 00:33:20.025 --> 00:33:26.075 <v Wojciech Wegrzynski>So you would measure like 20 seconds of the flow and you assume that it periodically repeats. 00:33:26.404 --> 00:33:28.384 <v Wojciech Wegrzynski>So this is how you would model wind in fire. 00:33:28.384 --> 00:33:32.265 <v Wojciech Wegrzynski>We, in, in practical engineering, we model ASET/RSET. 00:33:32.285 --> 00:33:33.994 <v Wojciech Wegrzynski>We need to know the fire development. 00:33:33.994 --> 00:33:38.285 <v Wojciech Wegrzynski>You know, you need 20 minutes of the fire, what will happen, how it will change over time. 00:33:38.704 --> 00:33:41.134 <v Wojciech Wegrzynski>So suddenly you're talking about a completely different simulation. 00:33:41.134 --> 00:33:59.951 <v Wojciech Wegrzynski>That's why I mentioned I can do 50 wind simulations when I can do one wind fire simulation, because for the reason I need to model my fire, on a transient scale, uh, and now the size of your mesh, if you use FDS, that does not only dictate your, spatial resolution. 00:34:00.685 --> 00:34:05.306 <v Wojciech Wegrzynski>It dictates your time step because of Courant-Friedrichs-Levy criterion FDS is used in MDs. 00:34:05.925 --> 00:34:09.675 <v Wojciech Wegrzynski>so changing the mesh, you change the timestamp of a simulation. 00:34:09.675 --> 00:34:14.085 <v Wojciech Wegrzynski>You're adding iterations, do simulation by having, um, a finer mesh. 00:34:14.596 --> 00:34:15.135 <v Wojciech Wegrzynski>So. 00:34:15.782 --> 00:34:22.023 <v Wojciech Wegrzynski>quickly becomes a very complicated matter that dictates if you're able to solve it or not. 00:34:22.023 --> 00:34:30.782 <v Wojciech Wegrzynski>You know, uh, because often when people will receive a CFD that will last a week or longer, they just give up, they rarely pursue such simulations. 00:34:30.782 --> 00:34:36.003 <v Wojciech Wegrzynski>And I hate it when they see a paper, we had to use a really horrible mesh because my laptop is not strong enough. 00:34:36.032 --> 00:34:38.492 <v Wojciech Wegrzynski>This is not the, this is not how science is done. 00:34:38.523 --> 00:34:40.503 <v Wojciech Wegrzynski>Like, you know, imagine certain set. 00:34:40.532 --> 00:34:48.043 <v Wojciech Wegrzynski>Uh, yeah, we think this particle exists, but we cannot confirm because the accelerator is, is just, uh, bad and we cannot afford the better one. 00:34:48.072 --> 00:34:50.179 <v Wojciech Wegrzynski>It's not that that that's a restraint. 00:34:50.179 --> 00:34:53.842 <v Wojciech Wegrzynski>You have to work around, but not, something you can justify a choice with. 00:34:54.652 --> 00:34:56.902 <v Wojciech Wegrzynski>Uh, so, so the choice of fish is really horrible. 00:34:57.023 --> 00:34:57.733 <v Wojciech Wegrzynski>And I think in this. 00:34:58.565 --> 00:35:07.952 <v Wojciech Wegrzynski>I'm highly inspired by Bert Blocken he's a leading scientist in the field, the field of wind engineering and field of, sports aerodynamics. 00:35:08.313 --> 00:35:13.690 <v Wojciech Wegrzynski>And Bert um, he, he was a pioneer who were doing this best practice guidelines for a wind. 00:35:14.050 --> 00:35:15.760 <v Wojciech Wegrzynski>And this is what inspired us. 00:35:16.269 --> 00:35:18.940 <v Wojciech Wegrzynski>And he showed very practical solutions to problems. 00:35:18.940 --> 00:35:20.320 <v Wojciech Wegrzynski>You know, they've run case studies. 00:35:20.320 --> 00:35:21.880 <v Wojciech Wegrzynski>They said, okay, this mesh is sufficient. 00:35:21.880 --> 00:35:23.980 <v Wojciech Wegrzynski>This is not, this is how you should build it. 00:35:24.159 --> 00:35:25.900 <v Wojciech Wegrzynski>This is the most efficient way you can do it. 00:35:25.900 --> 00:35:28.329 <v Wojciech Wegrzynski>And we wanted to transfer it into, into fire. 00:35:28.630 --> 00:35:30.070 <v Wojciech Wegrzynski>The thing that I think is. 00:35:30.940 --> 00:35:36.916 <v Wojciech Wegrzynski>Quite, surprising for fire people for us is that it's not sufficient to just make the mesh. 00:35:36.945 --> 00:35:42.045 <v Wojciech Wegrzynski>You have to measure the quality, and this is something I'm missing in many modeling studies. 00:35:42.076 --> 00:35:44.715 <v Wojciech Wegrzynski>Like people just choose and assume it's going to work. 00:35:44.746 --> 00:35:47.266 <v Wojciech Wegrzynski>But in wind you have to measure you. 00:35:47.266 --> 00:35:50.416 <v Wojciech Wegrzynski>You have to provide some metrics that this mesh is good. 00:35:50.416 --> 00:35:56.956 <v Wojciech Wegrzynski>Not on like the best is if you go convergence study and see, um, how a change in the mesh affects your outcomes. 00:35:56.956 --> 00:36:06.943 <v Wojciech Wegrzynski>But that in the fire is sometimes very difficult, to obtain because uh, many solvers do not really convert with, but like better mesh does not necessarily mean a better solution in fire. 00:36:07.032 --> 00:36:07.362 <v Wojciech Wegrzynski>Yeah. 00:36:07.932 --> 00:36:13.476 <v Wojciech Wegrzynski>And, and they have these metrics for like two blends, Y plus, uh, the scales of analysis. 00:36:13.835 --> 00:36:19.682 <v Wojciech Wegrzynski>I found it really interesting that, such metrics can be used and I wanted to expose the fire community. 00:36:20.518 --> 00:36:25.248 <v Wojciech Wegrzynski>White guy seeds, like the mesh meshes, like, uh, it's an important thing. 00:36:25.248 --> 00:36:25.864 <v Wojciech Wegrzynski>let's mesh it up. 00:36:25.864 --> 00:36:33.898 <v Wojciech Wegrzynski>Let's check it out before we go into modeling and there they're spending more of these best practice things in, in the paper, for sure. 00:36:34.240 --> 00:36:35.201 <v Guillermo Rein>yeah, that's key. 00:36:35.201 --> 00:36:37.661 <v Guillermo Rein>You, you are that you're describing the problem. 00:36:37.690 --> 00:36:39.490 <v Guillermo Rein>Rightly so as a multi-scale problem. 00:36:40.295 --> 00:36:46.266 <v Guillermo Rein>You have two phenomenon of importance, the fire, the wind, and each of them have different temporal and a specialist scales. 00:36:46.356 --> 00:36:48.215 <v Guillermo Rein>And as a modeler, you need to do both. 00:36:48.635 --> 00:36:50.615 <v Guillermo Rein>You cannot choose one or the other, you have to do both. 00:36:51.054 --> 00:36:51.686 <v Guillermo Rein>You're absolutely right. 00:36:51.686 --> 00:36:52.266 <v Guillermo Rein>I really like it. 00:36:52.266 --> 00:37:08.666 <v Guillermo Rein>How you emphasize how many people drop the wind when they try to do this and then not just going fire, maybe not for the best reasons, just because of the difficulty of the task, which means that the people who do it, like you must be celebrated and highlighted because this is the way 00:37:08.795 --> 00:37:22.503 <v Wojciech Wegrzynski>And my, you know, when we went into this OPOs grant, when we submitted that we want to study wind and fire interaction, we didn't just go that we want to see if a carpark will burn worse than, uh, when there's wind or when there's no wind. 00:37:22.922 --> 00:37:38.143 <v Wojciech Wegrzynski>We wanted to understand the consequences of low to meet, velocity wins on, on the fire, on smoke, to be able to, you know, give this better informed engineering judgment. 00:37:38.143 --> 00:37:49.402 <v Wojciech Wegrzynski>When we go into something like field experiments, you know, Often see, in papers from Windex, from fire experiments that a wind was moderate up to like five meters per second. 00:37:49.402 --> 00:37:53.393 <v Wojciech Wegrzynski>So we assumed it has no effect on, on fire worse. 00:37:53.543 --> 00:37:54.233 <v Wojciech Wegrzynski>We didn't know. 00:37:54.742 --> 00:37:59.753 <v Wojciech Wegrzynski>We have no idea if it had there not no one has ever done it in a parametric study. 00:38:00.023 --> 00:38:02.032 <v Wojciech Wegrzynski>So we have no idea. 00:38:02.063 --> 00:38:09.132 <v Wojciech Wegrzynski>What is the consequence of low velocity winds and from the initial work we've done, we've, we've seen these consequences. 00:38:09.132 --> 00:38:14.166 <v Wojciech Wegrzynski>Like we've seen that, one or two meters per second wind can already change things a lot. 00:38:14.706 --> 00:38:22.686 <v Wojciech Wegrzynski>And that's disturbing because that means everyone can, like, it's very rare that you would have wind conditions that would not affect you at all. 00:38:23.076 --> 00:38:34.106 <v Wojciech Wegrzynski>Now, when you do fire experiments in a laboratory, if you take my laboratory and you do the experiment With, a wooden building that I'm currently burning, like the ninth time. 00:38:34.795 --> 00:38:48.650 <v Wojciech Wegrzynski>If you show me the picture of that, of that fire plume, I can tell you which doors were open, you know, based on the shape of the plume, this is how often fragile fire is to external conditions. 00:38:48.710 --> 00:38:52.545 <v Wojciech Wegrzynski>And, when this overwhelmingly there, it's always there. 00:38:52.936 --> 00:38:55.965 <v Wojciech Wegrzynski>It is not the condition that appears and disappears. 00:38:55.996 --> 00:38:57.615 <v Wojciech Wegrzynski>It's just there in the background. 00:38:58.005 --> 00:39:02.516 <v Wojciech Wegrzynski>And if we want to understand, what are the consequences of it being there? 00:39:02.635 --> 00:39:06.985 <v Wojciech Wegrzynski>And I don't mean that it invalidates the data or something. 00:39:07.016 --> 00:39:08.936 <v Wojciech Wegrzynski>I just mean you need to know the uncertainty. 00:39:08.996 --> 00:39:17.485 <v Wojciech Wegrzynski>I had Francesco here last week and, uh, you seem to terrorize him about uncertainties and he's really good at them now, but this is important, you know? 00:39:17.505 --> 00:39:22.255 <v Wojciech Wegrzynski>No, no, you're your set and this and that, that gives you a better way to, to understand what you are. 00:39:23.039 --> 00:39:23.690 <v Guillermo Rein>Now thank you. 00:39:23.690 --> 00:39:27.659 <v Guillermo Rein>You, you are picturing a truly fascinating problem. 00:39:27.659 --> 00:39:49.311 <v Guillermo Rein>Multi-scale complex problem where the worst case scenario is far from evidence, which I think is very interesting because obviously in engineering, focusing on the worst case scenario is a tradition of itself, not the only one, but when the cannot be found, that is a hard, a good justification to invest into when modeling them. 00:39:50.036 --> 00:39:50.418 <v Guillermo Rein>Excellent. 00:39:50.418 --> 00:40:02.688 <v Guillermo Rein>So from the following on the multi-scale and the complexities of combining fire and wind, and one thing that wind and fire having common one, then definitely they do is that they'll never laminar. 00:40:02.989 --> 00:40:04.998 <v Guillermo Rein>The two of them are always turbulent. 00:40:05.358 --> 00:40:05.958 <v Guillermo Rein>So good. 00:40:05.989 --> 00:40:13.369 <v Guillermo Rein>So you are definitely going to be including turbulence in your model, but which model of Trulance and which model of combustion 00:40:13.474 --> 00:40:14.001 <v Wojciech Wegrzynski>oh, huh. 00:40:14.032 --> 00:40:14.871 <v Wojciech Wegrzynski>That's a tough one. 00:40:15.411 --> 00:40:16.612 <v Wojciech Wegrzynski>That's really a tough one. 00:40:16.994 --> 00:40:27.844 <v Wojciech Wegrzynski>I like this philosophy that, we need to understand physics to remove it from our, from our modeling, you know, I think Jose said something like that in Princeton lectures. 00:40:28.204 --> 00:40:34.510 <v Wojciech Wegrzynski>And, for combustion, we forget, for example, what is the added value of modeling combustion? 00:40:34.840 --> 00:40:46.637 <v Wojciech Wegrzynski>When I model a fire in my building, where I predefine the heat of combustion of my sample, I predefined the total heat release rate and I predefine . No. 00:40:46.637 --> 00:40:52.769 <v Wojciech Wegrzynski>So I predefined what amount of heat I generate I predefine what amount of smoke I generate. 00:40:53.130 --> 00:40:57.438 <v Wojciech Wegrzynski>And by my model, I give it geometrical constraints where it will burn. 00:40:57.438 --> 00:40:58.989 <v Guillermo Rein>It will just tell you where the flame is. 00:40:59.153 --> 00:41:01.164 <v Wojciech Wegrzynski>yeah, I think combustion to the. 00:41:02.074 --> 00:41:06.094 <v Wojciech Wegrzynski>It's like the same thing, but with additional steps in the meantime, which you have paid for. 00:41:06.634 --> 00:41:12.836 <v Wojciech Wegrzynski>So, if I do predefined everything there, I don't need combustion to do that. 00:41:12.867 --> 00:41:24.356 <v Wojciech Wegrzynski>I would need combustion if I wanted to know the oxygen concentration around, or I would like to know where the flame is, or I would leave the, the soot generation to be dictated by the physics model. 00:41:24.356 --> 00:41:29.121 <v Wojciech Wegrzynski>Or I would like to know rate of reactions, or I would have underbite, ventilated fire. 00:41:29.121 --> 00:41:37.554 <v Wojciech Wegrzynski>And I would like to understand if when pushing on the, small, uh, holes in the room can give sufficient oxygen or not, then sure. 00:41:37.673 --> 00:41:38.634 <v Wojciech Wegrzynski>I would model combustion. 00:41:38.934 --> 00:41:50.289 <v Wojciech Wegrzynski>But when I'm doing a simulation like that, I cannot model like I can model combustion, but it's just a fancy thing that gives me not that much and costs me a lot. 00:41:51.009 --> 00:41:52.748 <v Wojciech Wegrzynski>And with turbulence, it's the same. 00:41:53.405 --> 00:41:57.411 <v Wojciech Wegrzynski>You would have, two typical ways to model turbulence your flows. 00:41:57.711 --> 00:42:11.239 <v Wojciech Wegrzynski>When the air flows is giant vortices of air that are constantly spinning, that are moving around, dissipating into tiner and tiner ones until like, uh, there is at Kolmogrov scale, there is none left. 00:42:11.239 --> 00:42:21.108 <v Wojciech Wegrzynski>So, so that's, that's turbulence and someone defined it like turbulence is, is like pornography, you know, when you see it and he know what it is. 00:42:21.318 --> 00:42:29.059 <v Wojciech Wegrzynski>So it's very difficult to define that, but you have to model that, that, that the way, how, how air moves, and there are two ways you can do it. 00:42:29.599 --> 00:42:41.324 <v Wojciech Wegrzynski>You either average it over time, which we do with Reynolds Averaged Navier Stokes equations models, or you average in, in space. 00:42:41.324 --> 00:42:47.085 <v Wojciech Wegrzynski>And you solve for the movement in time, uh, which is used in Large Eddy Simulation. 00:42:47.085 --> 00:43:10.922 <v Wojciech Wegrzynski>That is the backbone of FDS, for example, The averaging in time approach is very efficient because you can go for a very long time steps, like one 10th of a second, maybe even more where you just assume that, the flow happens in the space, uh, you know, the average velocity, you know, The turbulence intensity. 00:43:10.922 --> 00:43:20.072 <v Wojciech Wegrzynski>So how turbulent the flow was, and you know, that this patient rates, so how this larger vortices is, has shed smaller ones and how this energy is spread around. 00:43:20.373 --> 00:43:28.742 <v Wojciech Wegrzynski>So this gives the solver a way to, to solve the momentum equation and give you a final flow field, which is averaged in time. 00:43:29.282 --> 00:43:34.463 <v Wojciech Wegrzynski>So when you take a picture of a fire, in this model, average in time, you don't see a beautiful fire. 00:43:34.472 --> 00:43:40.913 <v Wojciech Wegrzynski>You see like a cone or something with the different values, with different gradient of velocities or temperatures inside. 00:43:41.362 --> 00:43:44.663 <v Wojciech Wegrzynski>So that's one way, and this is very time efficient. 00:43:45.052 --> 00:43:48.652 <v Wojciech Wegrzynski>The only thing it cannot give you is the momentary value. 00:43:49.072 --> 00:43:54.800 <v Wojciech Wegrzynski>And they've already mentioned before that wind is, uh, gusts, which can be much higher than the average velocity. 00:43:55.159 --> 00:43:58.489 <v Wojciech Wegrzynski>So there's absolutely no way you can capture this with, with RANS modeling. 00:43:59.605 --> 00:44:05.155 <v Wojciech Wegrzynski>You can to some sort the biggest vertices, because you see them forming with this solution. 00:44:05.454 --> 00:44:14.775 <v Wojciech Wegrzynski>Especially if you go into very complex models, like Reynolds stress model, , then you have many more equations for every direction, how these dissipation happens. 00:44:15.125 --> 00:44:19.985 <v Wojciech Wegrzynski>You can capture, but not perfectly in LES modeling, you do the opposite. 00:44:20.554 --> 00:44:31.510 <v Wojciech Wegrzynski>You understand that there are multiple sizes of these vortices in the world And you understand that the big ones are the important ones because they move the air around. 00:44:31.811 --> 00:44:34.030 <v Wojciech Wegrzynski>And the tiny ones are not that much important. 00:44:34.030 --> 00:44:37.751 <v Wojciech Wegrzynski>They just like swirl until they dissipate and you just cut them. 00:44:38.050 --> 00:44:39.311 <v Wojciech Wegrzynski>Like I solved the big ones. 00:44:39.704 --> 00:44:42.378 <v Wojciech Wegrzynski>I forget about the small ones or I solved the small ones with. 00:44:42.472 --> 00:44:46.670 <v Wojciech Wegrzynski>a sub scale model, uh, and that's how FDS works. 00:44:46.760 --> 00:44:47.750 <v Wojciech Wegrzynski>It solves the big ones. 00:44:47.780 --> 00:44:54.076 <v Wojciech Wegrzynski>It doesn't, it approximates the tiny ones and the interface between them is related to the size of your cell. 00:44:54.076 --> 00:44:57.585 <v Wojciech Wegrzynski>So once again, we go back to the importance of the choice of your grid. 00:44:58.097 --> 00:45:07.643 <v Wojciech Wegrzynski>now this solution is expensive because the timestamps have to be very short in order to capture the movement of this beautiful, um, vortices. 00:45:08.393 --> 00:45:17.693 <v Wojciech Wegrzynski>What you gain for that is that you gain a beautiful image of, you know, this flames, puffing, smoke, moving in vortices. 00:45:18.193 --> 00:45:27.913 <v Wojciech Wegrzynski>it's, it's a much more beautiful, uh, when you look at it and it's much more realistic and you can capture the gusts in that, but the price you pay is. 00:45:28.858 --> 00:45:31.820 <v Wojciech Wegrzynski>Times 10 times hundreds of, RANS simulation. 00:45:32.061 --> 00:45:41.090 <v Wojciech Wegrzynski>And the funny, if you, and we'd done that if you take a LES simulation and you average the results, you get the image like in RANS you know, because you suddenly time average everything. 00:45:41.420 --> 00:45:45.605 <v Wojciech Wegrzynski>So, the choice of the turbulence is a difficult one in fire. 00:45:45.605 --> 00:45:50.045 <v Wojciech Wegrzynski>People often make this choice by choosing software. 00:45:50.164 --> 00:45:55.114 <v Wojciech Wegrzynski>If you choose FDS you use Les modeling, no other real choice. 00:45:55.594 --> 00:46:01.251 <v Wojciech Wegrzynski>If you go into like ANSYS, that's a fun thing because you have to choose, you have to tell there is no default model. 00:46:01.550 --> 00:46:02.960 <v Wojciech Wegrzynski>Default is, is laminar. 00:46:03.201 --> 00:46:07.867 <v Wojciech Wegrzynski>So you, you need to choose your model and to choose, you need to understand, for us. 00:46:07.887 --> 00:46:08.094 <v Wojciech Wegrzynski>we have. 00:46:08.632 --> 00:46:16.157 <v Wojciech Wegrzynski>Usually using either, K Epsilon RNG, that's a Renormalization Group, not random number generator. 00:46:16.157 --> 00:46:26.536 <v Wojciech Wegrzynski>How many people think it doesn't give random way as is the name of a group or the other one is k-omega SST and also works quite well for wind problems. 00:46:26.836 --> 00:46:30.467 <v Wojciech Wegrzynski>So, so these are the two that would be models of my choice. 00:46:31.097 --> 00:46:38.206 <v Wojciech Wegrzynski>And one day I would love to use Les for everything, but cannot afford it now, unfortunately. 00:46:38.447 --> 00:46:39.588 <v Guillermo Rein>And what about DNS? 00:46:39.648 --> 00:46:40.427 <v Guillermo Rein>That reg numerical 00:46:40.552 --> 00:46:40.972 <v Wojciech Wegrzynski>Yeah. 00:46:41.333 --> 00:46:42.123 <v Wojciech Wegrzynski>I mean, , that's 00:46:42.141 --> 00:46:42.711 <v Guillermo Rein>No, for wind, 00:46:42.717 --> 00:46:49.527 <v Wojciech Wegrzynski>um, this has been done till like Reynolds number of few thousands and, many people would use it direct number. 00:46:49.597 --> 00:47:29.016 <v Wojciech Wegrzynski>The simulation means you just solved the Navier Stokes equations, for every scale that this in your analysis, up to the tiniest vortices The question is, do you need that, the, the best practices of, of modeling, flows with larger, the simulation there's this beautiful paper, thing, 10 questions about Les, uh, by, by Pope, I would highly recommend to anyone who's dealing with, with flow problems in fire and, somewhere in there, there's a thing that if you solve 80% of the energy within the vortices, with Les, with the direct model and 20% you approximate with subrogate model, you're pretty much good. 00:47:29.556 --> 00:47:33.277 <v Wojciech Wegrzynski>So essentially four pieces you're solving directly. 00:47:33.277 --> 00:47:34.717 <v Wojciech Wegrzynski>One piece is approximated. 00:47:34.717 --> 00:47:36.456 <v Wojciech Wegrzynski>So your error is not that huge. 00:47:36.817 --> 00:47:40.141 <v Wojciech Wegrzynski>And that justifies why you don't need, DNS and DNS. 00:47:40.170 --> 00:47:43.880 <v Wojciech Wegrzynski>I mean, you can do DNS simulations for. 00:47:44.371 --> 00:47:48.152 <v Wojciech Wegrzynski>Problems, but it's prohibitively expensive. 00:47:48.211 --> 00:47:52.382 <v Wojciech Wegrzynski>It's just not with today's computers. 00:47:52.472 --> 00:47:55.291 <v Wojciech Wegrzynski>Not, not reachable and maybe not necessary. 00:47:55.472 --> 00:47:59.092 <v Wojciech Wegrzynski>I wonder, I don't think it is a, it's a nice validation technique, 00:47:59.153 --> 00:48:03.204 <v Guillermo Rein>this is a joy to interview you, but you, because I'm learning. 00:48:03.233 --> 00:48:07.284 <v Guillermo Rein>Um, and also I'm in best agreement with the things that you're 00:48:07.378 --> 00:48:09.478 <v Wojciech Wegrzynski>That was the point of the podcast you learned so much, man. 00:48:10.420 --> 00:48:12.440 <v Guillermo Rein>you are indeed a man of a Renaissance. 00:48:12.501 --> 00:48:16.490 <v Guillermo Rein>in modern times, the, there is a lot of things that you do that I value tremendously. 00:48:16.521 --> 00:48:23.420 <v Guillermo Rein>Um, one of them is that you are a scientist and an engineer, something very important for me also that you do experiments and you do modeling. 00:48:23.451 --> 00:48:27.201 <v Guillermo Rein>I know you, you, you, have more of a modeling background, but you also are involved in experiments. 00:48:27.891 --> 00:48:35.931 <v Guillermo Rein>, so in the work that we have discussing today of, of wind and fire modeling, what is the role that you see to experiments on the topic of validation? 00:48:35.971 --> 00:48:37.050 <v Wojciech Wegrzynski>that's, that's a good one. 00:48:37.530 --> 00:48:38.101 <v Wojciech Wegrzynski>That's a good one. 00:48:38.101 --> 00:48:45.153 <v Wojciech Wegrzynski>You actually once said about us that, we are a center for experimental fire science, and I saw that tweet and I was like, oh my God. 00:48:45.153 --> 00:48:49.384 <v Wojciech Wegrzynski>Yeah, that's actually what they want to become a center for experimental fire science. 00:48:49.384 --> 00:48:50.284 <v Wojciech Wegrzynski>That sounds so nice. 00:48:50.284 --> 00:48:51.094 <v Wojciech Wegrzynski>Let's build that up. 00:48:51.543 --> 00:48:56.213 <v Wojciech Wegrzynski>And, and we're trying our best to be, to be such a hub for wind. 00:48:56.244 --> 00:48:59.626 <v Wojciech Wegrzynski>Wind engineering is essentially an experimental field. 00:48:59.726 --> 00:49:03.117 <v Wojciech Wegrzynski>, almost everything we know about it comes from experiments in wind tunnels. 00:49:03.507 --> 00:49:16.166 <v Wojciech Wegrzynski>So even the best practices for CFD in many cases, refer to the best practices of wind tunnel engineering, and experiments in wind tunnels like the blockage radio you would like. 00:49:16.721 --> 00:49:23.443 <v Wojciech Wegrzynski>how much of the space in your domain, you can block with buildings to make sure that, you don't affect the flow inside. 00:49:23.773 --> 00:49:25.963 <v Wojciech Wegrzynski>So that comes from the, from the tunnel experiments. 00:49:25.963 --> 00:49:26.833 <v Wojciech Wegrzynski>So that's beautiful. 00:49:27.103 --> 00:49:37.130 <v Wojciech Wegrzynski>Now when with the wind and fire, experimenting is very difficult for two reasons, you either can achieve, the scale. 00:49:37.340 --> 00:49:41.721 <v Wojciech Wegrzynski>So you can go into full scale and you can achieve full scale. 00:49:42.710 --> 00:49:44.905 <v Wojciech Wegrzynski>And include the wind effort in that fire. 00:49:44.905 --> 00:49:52.405 <v Wojciech Wegrzynski>If you burn a building outdoors there's winds, you can have wind FX in that experiment, but you do not get to choose the wins. 00:49:52.494 --> 00:49:57.954 <v Wojciech Wegrzynski>You know, you, you work with what the nature has G gave in at that particular moment. 00:49:58.414 --> 00:50:03.304 <v Wojciech Wegrzynski>Or you can go into wind tunnel and you can choose the wind. 00:50:03.605 --> 00:50:08.525 <v Wojciech Wegrzynski>You have the perfect choice of what wind boundary condition you have. 00:50:09.244 --> 00:50:15.094 <v Wojciech Wegrzynski>But you have to go into scale fire, which is not a real fire, which is difficult in interpretation. 00:50:15.635 --> 00:50:26.088 <v Wojciech Wegrzynski>So I think the only people who can do it both are IBHS in us, they, they break the rules because they have a giant wind tunnel where you can put burning buildings inside. 00:50:26.088 --> 00:50:28.518 <v Wojciech Wegrzynski>So, so th they, they broke the law there. 00:50:28.728 --> 00:50:29.717 <v Wojciech Wegrzynski>It should be prohibited. 00:50:30.257 --> 00:50:43.061 <v Wojciech Wegrzynski>It's, it's unfair advantage over the rest of us, but, but these guys can do both everyone else on the planet has to either, run the fire experiments in whatever, when do you find, or, or scaled down. 00:50:43.331 --> 00:50:45.460 <v Wojciech Wegrzynski>And th this is very difficult. 00:50:45.460 --> 00:51:00.362 <v Wojciech Wegrzynski>And in our project, you know, we choose the route of, numerical modeling as the fundamental tool of research, supported by wind tunnel modeling for, In terms of pressures on the buildings. 00:51:00.663 --> 00:51:19.380 <v Wojciech Wegrzynski>So we know that we are unable to model wind and fire together, but we want to build a mock-up of the city that we are modeling in a computer in the wind tunnel, run, wind experiment in it, and figure out if the pressures on facades are accurate. 00:51:19.409 --> 00:51:22.889 <v Wojciech Wegrzynski>If the flows are the same in the CFD and in the wind tunnel. 00:51:22.980 --> 00:51:28.409 <v Wojciech Wegrzynski>So it would give us the capability to say, okay, to some salt, we have validated the wind model. 00:51:28.409 --> 00:51:30.389 <v Wojciech Wegrzynski>That wind solution is correct in here. 00:51:31.581 --> 00:51:48.389 <v Wojciech Wegrzynski>, and again, for me as someone who loves to work with, with full-scale experiments, this is also, as I mentioned, important thing to understand, to what extent when you meet on the field impacts your far expand meant, and to be able to quantify that in, in a way or another, that's fun. 00:51:48.695 --> 00:51:56.146 <v Wojciech Wegrzynski>But yeah, there's definitely in the future in experimenting with wind, it's just hard to put fire in there unless you are IBHS 00:51:56.505 --> 00:51:56.896 <v Guillermo Rein>Awesome. 00:51:57.273 --> 00:52:00.989 <v Guillermo Rein>Thank you Wojciech I do have two more questions, for the interview today. 00:52:00.989 --> 00:52:02.248 <v Guillermo Rein>I wish we could have a follow-up. 00:52:02.369 --> 00:52:05.039 <v Guillermo Rein>Uh, maybe when, when we have the episode a hundred, you invite me 00:52:05.228 --> 00:52:05.739 <v Wojciech Wegrzynski>yeah. 00:52:06.009 --> 00:52:12.159 <v Wojciech Wegrzynski>Uh, to, to clear all the misconceptions that were said in episode 50 and why it's completely different. 00:52:13.862 --> 00:52:21.793 <v Guillermo Rein>so the first is, do you have a message for young engineers and young scientists that are entering into a topic of Fire and wind. 00:52:21.813 --> 00:52:24.842 <v Guillermo Rein>When do you, is there anything that you want to tell them specifically? 00:52:24.842 --> 00:52:29.108 <v Guillermo Rein>Not to the old dinosaurs, like, like us step to the two younger ones to the much younger ones. 00:52:29.186 --> 00:52:40.096 <v Wojciech Wegrzynski>Um, it's complicated, but it shouldn't hold you back from doing it the best you can, the interaction is so rich. 00:52:40.563 --> 00:52:44.115 <v Wojciech Wegrzynski>There is probably not a single solution for that. 00:52:44.115 --> 00:52:47.715 <v Wojciech Wegrzynski>You know, it will always be a problem of your. 00:52:48.561 --> 00:52:53.570 <v Wojciech Wegrzynski>Architecture of your wind boundary conditions of your fire. 00:52:53.570 --> 00:53:00.831 <v Wojciech Wegrzynski>It will always be something very unique that you find, and it is, it is hard, but it is worth it. 00:53:00.831 --> 00:53:14.907 <v Wojciech Wegrzynski>I think, I think it gets you on a completely different level of understanding the phenomenon you're trying, especially the wind can be the driving force for many phenomena. 00:53:15.597 --> 00:53:15.867 <v Wojciech Wegrzynski>I guess. 00:53:15.867 --> 00:53:18.657 <v Wojciech Wegrzynski>That's, that's the first question you should ask yourself. 00:53:19.166 --> 00:53:31.797 <v Wojciech Wegrzynski>Do I, by the literature study by the overview of the field, they think a wind can be the driving force in here, because if it's not, then maybe it's not worth it. 00:53:31.827 --> 00:53:39.835 <v Wojciech Wegrzynski>But if there's any chance that wind can be a driving force in the thing you're trying. 00:53:40.914 --> 00:53:43.824 <v Wojciech Wegrzynski>If you are omit it you just ommited the driving force. 00:53:43.824 --> 00:53:49.168 <v Wojciech Wegrzynski>So, that's not, a great solution and it should not admit it to save time or to save computational resources. 00:53:49.168 --> 00:53:50.157 <v Wojciech Wegrzynski>You never should do that. 00:53:50.157 --> 00:53:52.958 <v Wojciech Wegrzynski>You should, try and use it. 00:53:54.293 --> 00:54:01.018 <v Wojciech Wegrzynski>you should also try to see if there are simpler models than let's say CFD that we're using that can do both. 00:54:01.557 --> 00:54:13.478 <v Wojciech Wegrzynski>Like if we go back to the tunnel example that we've discussed, if you wanted to solve that problem with, CFD, it will be very expensive, difficult, and long solution solution to do. 00:54:14.047 --> 00:54:15.367 <v Wojciech Wegrzynski>It would be ridiculous to do. 00:54:15.547 --> 00:54:24.222 <v Wojciech Wegrzynski>We had the luck, the tunnel was built and we could take measurements and approximate the coefficients for portals with, with measurements, but it would seem that it would be ridiculous. 00:54:24.942 --> 00:54:38.525 <v Wojciech Wegrzynski>However, if you want it to solve the same thing with the simple momentum equation, You know, and, and put a wind as one of the boundaries in that reduced order model, you can do it in one, two days and have really decent solution. 00:54:38.525 --> 00:54:41.969 <v Wojciech Wegrzynski>And that's what we did essentially in the end of the, of the test. 00:54:42.389 --> 00:54:54.612 <v Wojciech Wegrzynski>So, it's complicated, but they may be reduced or their models that can allow you to solve your issue and understand this holistic problem of wind and fire interaction in your case. 00:54:55.213 --> 00:55:00.306 <v Wojciech Wegrzynski>And then when you go into final modeling, maybe , you will know when is the driving force and what is not. 00:55:00.666 --> 00:55:20.106 <v Wojciech Wegrzynski>Then if the driving force is improbable, because that's one in a thousand a year hurricane, you can cut it out and you're safe, but you have a proof why, if it's a driving for steel, then maybe you need to do some experiments, do some modeling, go, go deeper in it and see to what extent it is influencing your solution. 00:55:21.262 --> 00:55:28.467 <v Wojciech Wegrzynski>Or if you don't feel like that because it's overwhelmingly, because I know you can jump into the loophole, which will be overwhelming. 00:55:28.467 --> 00:55:33.717 <v Wojciech Wegrzynski>I mean, that's where we jumped and I know what I have went through to achieve my results. 00:55:33.717 --> 00:55:41.708 <v Wojciech Wegrzynski>So, it can be an overwhelming, local, but you know, there are people there who do that and just open your mind and collaborate. 00:55:41.708 --> 00:55:45.608 <v Wojciech Wegrzynski>And then like I found my Tomek who's the brilliant wind engineer. 00:55:45.608 --> 00:55:46.867 <v Wojciech Wegrzynski>And he helped me tremendously. 00:55:46.867 --> 00:55:48.367 <v Wojciech Wegrzynski>You need to find one for yourself. 00:55:48.367 --> 00:55:55.987 <v Wojciech Wegrzynski>And, uh, he doesn't have the, it doesn't have to be an expert in fire, but they may be an expert in solving your particular problems. 00:55:55.987 --> 00:55:57.097 <v Wojciech Wegrzynski>So, yeah. 00:55:57.577 --> 00:55:59.728 <v Wojciech Wegrzynski>And you don't have to take everything on your own. 00:55:59.757 --> 00:56:00.608 <v Wojciech Wegrzynski>Just collaborate. 00:56:00.876 --> 00:56:06.726 <v Guillermo Rein>that's an excellent call for the younger generations to embrace multidisciplinarity. 00:56:06.936 --> 00:56:13.327 <v Guillermo Rein>Um, and not just do it by themselves, but during a team that sounds like a very modern approach to science. 00:56:13.746 --> 00:56:19.027 <v Guillermo Rein>Also, I like that you are inviting them to go into a topic that is you are warning them. 00:56:19.027 --> 00:56:21.637 <v Guillermo Rein>That is challenging, but you are promising them. 00:56:21.666 --> 00:56:22.297 <v Guillermo Rein>That is reward. 00:56:23.032 --> 00:56:24.172 <v Guillermo Rein>And that's fantastic. 00:56:24.442 --> 00:56:33.364 <v Guillermo Rein>And then the last question then your audience and I, all of us would like to know what's next for you on not, I mean, you have a whole lifetime of fire science.. 00:56:33.385 --> 00:56:37.074 <v Guillermo Rein>We know that what we mean is in wind and fire modeling. 00:56:37.074 --> 00:56:38.155 <v Guillermo Rein>What's what's next for you? 00:56:38.275 --> 00:56:38.434 <v Wojciech Wegrzynski>Yeah. 00:56:38.434 --> 00:56:43.735 <v Wojciech Wegrzynski>W within the phone, a couple of modeling, part three, hopefully in fire technology.. 00:56:44.782 --> 00:56:54.268 <v Wojciech Wegrzynski>so we're in the middle of this, and granddad was mentioned where we want to see complete image of wind and fire interaction on over a single building. 00:56:54.958 --> 00:56:58.498 <v Wojciech Wegrzynski>The what extent the wind would be a driving force in the building. 00:56:58.887 --> 00:57:11.425 <v Wojciech Wegrzynski>Can we define in which scenarios the wind was the driving force in which it was not, then that the mind, the probabilities of this scenarios to go into quite the complete risk. 00:57:11.547 --> 00:57:18.657 <v Wojciech Wegrzynski>Based analysis on, was it a major factor in overall safety of the building or not? 00:57:19.228 --> 00:57:31.235 <v Wojciech Wegrzynski>And if it was, to what extent that that will answer a lot of questions on how wind influences fires in general, because this will be a nice case study to refer to. 00:57:31.628 --> 00:57:35.195 <v Wojciech Wegrzynski>and I, I hope like we're completing the preparation stage. 00:57:36.139 --> 00:57:39.289 <v Wojciech Wegrzynski>So there is just this few thousand CFDs to be done and we're, we're good. 00:57:39.650 --> 00:57:43.320 <v Wojciech Wegrzynski>So, so that's, that's the nearest future for that. 00:57:43.320 --> 00:57:48.690 <v Wojciech Wegrzynski>And I have brilliant postdoc Paulina Jaminska-Gadomska, who's working on this with me. 00:57:48.690 --> 00:57:53.014 <v Wojciech Wegrzynski>She's a, wind engineered, trained by Thomas, my, my friend from Lublin. 00:57:53.675 --> 00:57:55.264 <v Wojciech Wegrzynski>So she's very good at it. 00:57:55.264 --> 00:57:59.795 <v Wojciech Wegrzynski>And then she was a little overwhelmed with fire aspect, but, it's under control. 00:58:00.235 --> 00:58:03.815 <v Wojciech Wegrzynski>She's very happy doing that and she's discovering cool fire. 00:58:04.175 --> 00:58:08.375 <v Wojciech Wegrzynski>Like we are, we're discovering wind and that's an exciting thing for her, I think as well. 00:58:08.675 --> 00:58:09.635 <v Wojciech Wegrzynski>So that's the project. 00:58:10.235 --> 00:58:15.974 <v Wojciech Wegrzynski>Uh, we also build a wind tunnel in, in ITB for modeling, natural ventilators. 00:58:16.418 --> 00:58:25.501 <v Wojciech Wegrzynski>it's more like a business thing, you know, to, to investigate the performance of natural ventilators, according to standards, but we are doing funny things with it. 00:58:25.561 --> 00:58:29.773 <v Wojciech Wegrzynski>Um, we're doing, Photovoltaic panel natural ventilator interaction. 00:58:30.161 --> 00:58:43.389 <v Wojciech Wegrzynski>we want to, do scaled facades, especially scale facade tests, you know, and, and, and quantify to what extent an outdoor test is, uh, is changing the outcomes. 00:58:43.422 --> 00:58:44.862 <v Guillermo Rein>I don't have that question with you too. 00:58:45.313 --> 00:58:46.422 <v Wojciech Wegrzynski>that's an interesting question. 00:58:46.422 --> 00:58:46.963 <v Wojciech Wegrzynski>This isn't it. 00:58:46.992 --> 00:58:50.650 <v Wojciech Wegrzynski>So this such a topic to be answered. 00:58:50.650 --> 00:59:02.932 <v Wojciech Wegrzynski>And, I really liked the interaction of things on the building roofs because I honestly hate the current way, how natural ventilators are put on the market based on their individual CV value. 00:59:03.532 --> 00:59:07.717 <v Wojciech Wegrzynski>When, we know, Different the performance of the ventilators is on the roof. 00:59:07.746 --> 00:59:09.637 <v Wojciech Wegrzynski>Like every ventilator has done performance. 00:59:09.637 --> 00:59:11.586 <v Wojciech Wegrzynski>You cannot just standardize that. 00:59:11.617 --> 00:59:12.577 <v Wojciech Wegrzynski>It's very difficult. 00:59:12.717 --> 00:59:19.170 <v Wojciech Wegrzynski>So one day I would like to abolish that probably as evolution there, the, the standard to test a curve. 00:59:19.170 --> 00:59:28.530 <v Wojciech Wegrzynski>It's not possible it's overwhelmingly on the market, but yeah, these are the next, the next nearest steps in, in wind and fire. 00:59:28.530 --> 00:59:39.010 <v Wojciech Wegrzynski>And we're taking it one step at a time, going deeper and deeper, understanding it better and better and hope to provide a broad answers to this narrow question. 00:59:39.010 --> 00:59:40.690 <v Wojciech Wegrzynski>This wind influence 00:59:40.789 --> 00:59:46.730 <v Guillermo Rein>Are you, are you going to have open tours to your tunnel facility, to your tunnel? 00:59:46.880 --> 00:59:47.329 <v Guillermo Rein>wind tunnel? 00:59:47.420 --> 00:59:50.777 <v Wojciech Wegrzynski>If you're ever in Poland, the wind tunnel is in Pionki and, 00:59:50.789 --> 00:59:52.769 <v Guillermo Rein>I'm definitely, I'm already in the in the list. 00:59:52.769 --> 00:59:54.630 <v Guillermo Rein>I wonder about the audience. 00:59:55.065 --> 00:59:56.355 <v Wojciech Wegrzynski>Everyone's in invited. 00:59:56.355 --> 00:59:58.574 <v Wojciech Wegrzynski>If you ended up in Poland, just give me a call. 00:59:58.844 --> 00:59:59.925 <v Wojciech Wegrzynski>We can arrange it. 00:59:59.925 --> 01:00:01.425 <v Wojciech Wegrzynski>It's a good photo opportunity. 01:00:01.525 --> 01:00:02.545 <v Wojciech Wegrzynski>The table rotates now. 01:00:02.545 --> 01:00:08.135 <v Wojciech Wegrzynski>So you can take a like musical music video type of, shoots in insight. 01:00:08.465 --> 01:00:09.574 <v Wojciech Wegrzynski>It's a great thing. 01:00:09.815 --> 01:00:12.184 <v Wojciech Wegrzynski>We can measure your aerodynamics if you want. 01:00:13.804 --> 01:00:15.411 <v Wojciech Wegrzynski>My mine is horrible. 01:00:15.416 --> 01:00:16.137 <v Guillermo Rein>That's fun. 01:00:16.474 --> 01:00:24.697 <v Guillermo Rein>You should organize a conference, and you can invite, some of your most successful podcast episodes to, to, to be, part of a conference. 01:00:25.117 --> 01:00:27.757 <v Wojciech Wegrzynski>that may be a possibility we'll see in the future. 01:00:27.757 --> 01:00:32.077 <v Wojciech Wegrzynski>I think it will be it's generally, it would be great to finally meet again. 01:00:32.802 --> 01:00:35.503 <v Wojciech Wegrzynski>People like real people, not on the screen. 01:00:35.503 --> 01:00:42.103 <v Wojciech Wegrzynski>And I cannot wait for, for the, for this chance to finally reemerge the damage already. 01:00:42.103 --> 01:00:43.152 <v Wojciech Wegrzynski>So I'm happy. 01:00:43.396 --> 01:00:45.463 <v Guillermo Rein>What'd you, what was, what is the name of your postdoc? 01:00:45.463 --> 01:00:45.552 <v Guillermo Rein>You 01:00:45.777 --> 01:00:47.807 <v Wojciech Wegrzynski>Uh, Paulina Jaminska-Gadomska 01:00:47.914 --> 01:00:48.242 <v Guillermo Rein>Perfect. 01:00:48.242 --> 01:01:02.213 <v Guillermo Rein>So I think I'm going to propose that there is, if there is a quote for this episode, I think the quote should be, you might want to actually repeat it if you agree, and then we make it, your quote is, is the court is find your Tomek and find your Paulina 01:01:02.777 --> 01:01:03.197 <v Wojciech Wegrzynski>yeah. 01:01:03.572 --> 01:01:06.483 <v Guillermo Rein>And then if people want to know what that means, they actually have to go through the. 01:01:07.628 --> 01:01:07.947 <v Wojciech Wegrzynski>Yeah. 01:01:08.327 --> 01:01:09.998 <v Wojciech Wegrzynski>That's the that's brilliant. 01:01:10.038 --> 01:01:17.278 <v Wojciech Wegrzynski>And, , many people are meeting a wall trying to solve issues where others have solutions for and. 01:01:18.378 --> 01:01:20.838 <v Wojciech Wegrzynski>You don't need to know everything. 01:01:21.858 --> 01:01:27.768 <v Wojciech Wegrzynski>Sometimes it's, it's way more than sufficient to know who knows it and then just work together. 01:01:27.798 --> 01:01:43.199 <v Wojciech Wegrzynski>And I believe in this collaborative minds of scientists, and it's also a philosophy that you did, you implement over your students, this openness, collaborative environment in which, the best things can emerge from. 01:01:43.228 --> 01:01:48.577 <v Wojciech Wegrzynski>I think it's very rarely that a single person creates a groundbreaking 01:01:48.978 --> 01:01:50.509 <v Guillermo Rein>not not in the 21st century. 01:01:50.639 --> 01:01:50.929 <v Guillermo Rein>Yeah. 01:01:51.032 --> 01:01:52.922 <v Guillermo Rein>Maybe Newton, maybe Newton could do that. 01:01:53.163 --> 01:01:53.313 <v Guillermo Rein>Now. 01:01:53.413 --> 01:01:54.222 <v Wojciech Wegrzynski>that was very hard. 01:01:54.222 --> 01:01:54.672 <v Wojciech Wegrzynski>Yes. 01:01:55.123 --> 01:01:59.615 <v Guillermo Rein>And the last question is there is another type of fire smoke. 01:01:59.646 --> 01:02:16.076 <v Guillermo Rein>And when, which is related to the Russian invasion, Ukraine, Putins war, that is actually as we speak ongoing, not far from you, but, I mean, this is probably not something that you want to model, but, is there other ways that you are thinking of how you can help these horrific events that, that are happening very close to. 01:02:16.905 --> 01:02:21.576 <v Wojciech Wegrzynski>In terms of, fire research, you know, and especially fire wind research. 01:02:22.025 --> 01:02:34.416 <v Wojciech Wegrzynski>There was awfully lot done in terms of understanding how efficiently we can burn cities of our enemies probably more research on how can we efficiently destroy them? 01:02:34.715 --> 01:02:36.215 <v Wojciech Wegrzynski>How can we efficiently protect? 01:02:36.396 --> 01:02:50.525 <v Wojciech Wegrzynski>Unfortunately, the war time research, the post-war time research, one of the major threats related to nuclear weapon use is the radiation costs and the ignition cost by this, uh, this weapon and how fires will spread. 01:02:50.916 --> 01:03:03.286 <v Wojciech Wegrzynski>There was immense amount of work done on how fire spreads in cities, how fire, these choice cities, but also how to, in a way, make sure that your city is hit less than the others city. 01:03:04.309 --> 01:03:09.099 <v Wojciech Wegrzynski>fire engineers have surprisingly long, history of researching that field. 01:03:09.518 --> 01:03:12.909 <v Wojciech Wegrzynski>I just think it's not my generation and not yours generation. 01:03:12.909 --> 01:03:17.889 <v Wojciech Wegrzynski>It was the generation of the dinosaurs before us who, who were much into that. 01:03:17.889 --> 01:03:20.775 <v Wojciech Wegrzynski>And there, there are NATO guidebooks about that. 01:03:21.166 --> 01:03:26.266 <v Wojciech Wegrzynski>There's the Pitts review that I mentioned that there's lots of literature that can be used. 01:03:26.896 --> 01:03:29.155 <v Wojciech Wegrzynski>And, yeah, fire is, is a weapon. 01:03:30.025 --> 01:03:31.585 <v Wojciech Wegrzynski>Of course it is a weapon. 01:03:32.206 --> 01:03:39.139 <v Wojciech Wegrzynski>the second issue that I think that is related to war, but not directly to military actions is the safety of the people who escaped the world. 01:03:39.829 --> 01:03:44.478 <v Wojciech Wegrzynski>And there's 13 million Ukrainians relocated by the war. 01:03:44.509 --> 01:03:47.353 <v Wojciech Wegrzynski>Imagine that's the country that has 40 few million people. 01:03:47.353 --> 01:03:51.432 <v Wojciech Wegrzynski>And 13 million of them are not in their home because of the war. 01:03:51.463 --> 01:03:52.753 <v Wojciech Wegrzynski>One third of the country. 01:03:53.503 --> 01:03:53.833 <v Wojciech Wegrzynski>And. 01:03:54.335 --> 01:04:00.275 <v Wojciech Wegrzynski>To the best of my knowledge, they don't have huge camps yet, but probably it's Inevitable. 01:04:00.275 --> 01:04:11.552 <v Wojciech Wegrzynski>if this continues and then we go into the struggle of providing fire safety to them and they have, they have bigger problems than fire on their head, you know? 01:04:11.947 --> 01:04:14.838 <v Wojciech Wegrzynski>they don't really have a chance to care about it that much. 01:04:15.438 --> 01:04:25.786 <v Wojciech Wegrzynski>And I know your director at Kindling . And, I admire that company a lot because you guys are doing what these people cannot or it's not on their mind at the moment. 01:04:25.786 --> 01:04:36.329 <v Wojciech Wegrzynski>And I think providing fire safety to those who escape or is tremendous value, and it is very important to understand the challenges they go through. 01:04:37.318 --> 01:04:47.606 <v Wojciech Wegrzynski>And if there are solutions that can be given advice to them that will solve some of the problems that they may not even consider a problem, but they are problems. 01:04:48.025 --> 01:04:59.103 <v Wojciech Wegrzynski>So, I think it's a difficult subject, but I'm very, very happy that there are people like, like people on Kindling who, who actively work on that and, already are looking into solutions. 01:04:59.103 --> 01:04:59.432 <v Wojciech Wegrzynski>So, 01:05:00.182 --> 01:05:00.393 <v Guillermo Rein>yeah. 01:05:00.512 --> 01:05:04.893 <v Guillermo Rein>I know Daniella is who spoke in your, in your podcast. 01:05:04.922 --> 01:05:08.612 <v Guillermo Rein>It's just always talking to you in how they can help. 01:05:09.182 --> 01:05:14.043 <v Guillermo Rein>It's just that as, as engineers know, we, we try to fight fire as an accident. 01:05:14.592 --> 01:05:25.186 <v Guillermo Rein>it is very, very sad to have to work sometimes into fire protection or protection of people when it's not an accident when it's the military, abuse of someone else that that is very hard. 01:05:25.215 --> 01:05:26.445 <v Guillermo Rein>That's very unfair. 01:05:27.351 --> 01:05:29.471 <v Guillermo Rein>And there's one, they call is higher, right. 01:05:29.471 --> 01:05:33.150 <v Guillermo Rein>To help those that are being, hurt, uh, left and right. 01:05:33.210 --> 01:05:34.201 <v Guillermo Rein>Um, by, 01:05:34.681 --> 01:05:34.918 <v Wojciech Wegrzynski>yeah, 01:05:34.923 --> 01:05:36.574 <v Guillermo Rein>for very valid reasons. 01:05:36.753 --> 01:05:52.753 <v Wojciech Wegrzynski>But thankfully, you know, the work that has been done, the whole fire protection engineering industry, all the work on the fire resistance, all the work on the reaction to fire of materials, our cities are built different than a hundred years ago. 01:05:53.202 --> 01:05:54.822 <v Wojciech Wegrzynski>They are more fire resilient. 01:05:54.853 --> 01:05:56.773 <v Wojciech Wegrzynski>They are more fire safe. 01:05:57.282 --> 01:06:05.972 <v Wojciech Wegrzynski>So thankfully in a passive way, by stopping this accidental fires, we're also making the job of the incinerators more difficult than that. 01:06:06.003 --> 01:06:14.943 <v Wojciech Wegrzynski>That's probably one, one good thing again, from our fields too, that the people in Ukraine at the moment, there's always a war in the world. 01:06:14.943 --> 01:06:18.333 <v Wojciech Wegrzynski>So many others are affected by wars everywhere. 01:06:18.753 --> 01:06:20.492 <v Wojciech Wegrzynski>And the fire is a part of them always. 01:06:20.864 --> 01:06:21.253 <v Guillermo Rein>Okay. 01:06:21.704 --> 01:06:25.153 <v Guillermo Rein>Thank you, Wojciech was an absolute joy to interview you. 01:06:25.213 --> 01:06:30.717 <v Guillermo Rein>Um, there was my first interview and I interviewed someone and I, I did adjust. 01:06:30.717 --> 01:06:34.141 <v Guillermo Rein>And following your book, I listened to you weekly, so I learned how you do it. 01:06:34.141 --> 01:06:36.601 <v Guillermo Rein>I thought I'll try something similar to that. 01:06:36.706 --> 01:06:38.775 <v Wojciech Wegrzynski>thank you, Guillermo you did a great job on that. 01:06:38.775 --> 01:06:40.516 <v Wojciech Wegrzynski>It was a huge pleasure to be interviewed. 01:06:41.115 --> 01:06:43.255 <v Wojciech Wegrzynski>I have a fresh page, no notes on my eyes. 01:06:43.335 --> 01:06:47.186 <v Wojciech Wegrzynski>So refreshing, you know, time I do it, I it's. 01:06:47.186 --> 01:06:48.195 <v Wojciech Wegrzynski>It's a new today. 01:06:48.346 --> 01:06:48.766 <v Wojciech Wegrzynski>Yes. 01:06:48.795 --> 01:06:49.215 <v Wojciech Wegrzynski>Thank you. 01:06:49.456 --> 01:06:53.206 <v Wojciech Wegrzynski>Well, thank you for, for doing that and, uh, yeah. 01:06:53.235 --> 01:06:58.079 <v Wojciech Wegrzynski>Happy to lend this, tube to spread important messages in the future as well. 01:06:58.559 --> 01:06:59.219 <v Wojciech Wegrzynski>Cheers, man. 01:06:59.541 --> 01:06:59.900 <v Guillermo Rein>thank you. 01:06:59.900 --> 01:07:00.501 <v Guillermo Rein>Thank you so much. 01:07:02.193 --> 01:07:02.922 <v Wojciech Wegrzynski>Yeah, that's it. 01:07:03.523 --> 01:07:05.773 <v Wojciech Wegrzynski>It's me again in the driver's seat. 01:07:05.833 --> 01:07:11.083 <v Wojciech Wegrzynski>Thank you so much Guillermo for taking it over for one episode and thank you. 01:07:11.472 --> 01:07:15.012 <v Wojciech Wegrzynski>So much actually for proposing thing this and organizing it, then. 01:07:15.612 --> 01:07:17.052 <v Wojciech Wegrzynski>I was a nice surprise and. 01:07:17.195 --> 01:07:20.016 <v Wojciech Wegrzynski>It was way more fun than I thought it will be in. 01:07:20.733 --> 01:07:25.623 <v Wojciech Wegrzynski>Actually it's surprising how much the perspective changes from host to guest. 01:07:26.014 --> 01:07:30.063 <v Wojciech Wegrzynski>It was a, I guess, a much needed experience for myself. 01:07:30.304 --> 01:07:32.134 <v Wojciech Wegrzynski>So I can torture my guests better actually. 01:07:32.643 --> 01:07:36.213 <v Wojciech Wegrzynski>And anyway, I hope all of you enjoyed the wind and fire things. 01:07:36.213 --> 01:07:37.264 <v Wojciech Wegrzynski>I had to say. 01:07:37.773 --> 01:07:40.023 <v Wojciech Wegrzynski>It's a fantastic topic of science. 01:07:40.324 --> 01:07:48.664 <v Wojciech Wegrzynski>It's a subject that's never ending because as many buildings as many fire and wind the interactions there will be. 01:07:49.083 --> 01:07:53.463 <v Wojciech Wegrzynski>And I think if we want to build a fire safe society, we need. 01:07:53.463 --> 01:07:54.184 <v Wojciech Wegrzynski>To understand. 01:07:54.603 --> 01:07:55.893 <v Wojciech Wegrzynski>This phenomenon better. 01:07:56.434 --> 01:07:57.364 <v Wojciech Wegrzynski>My team and I. 01:07:57.454 --> 01:08:04.233 <v Wojciech Wegrzynski>We are working very hard to understand it and build guidance for the rest of the community. 01:08:04.233 --> 01:08:05.434 <v Wojciech Wegrzynski>And we are very. 01:08:05.463 --> 01:08:08.434 <v Wojciech Wegrzynski>Very happy to see other groups interested in the subject. 01:08:08.704 --> 01:08:10.173 <v Wojciech Wegrzynski>Uh, other researchers pursuing. 01:08:10.273 --> 01:08:12.434 <v Wojciech Wegrzynski>The research in the field of wind and fire. 01:08:12.884 --> 01:08:15.704 <v Wojciech Wegrzynski>It makes me very happy to see how this field. 01:08:15.733 --> 01:08:18.134 <v Wojciech Wegrzynski>It is growing and so much. 01:08:18.463 --> 01:08:20.654 <v Wojciech Wegrzynski>Great stuff will come out of that. 01:08:21.163 --> 01:08:23.533 <v Wojciech Wegrzynski>And yeah, I will not torture you anymore. 01:08:23.564 --> 01:08:25.234 <v Wojciech Wegrzynski>With wind and fire science. 01:08:25.234 --> 01:08:29.014 <v Wojciech Wegrzynski>I think if you sustain so long, uh, You're good. 01:08:30.213 --> 01:08:33.198 <v Wojciech Wegrzynski>And, thank you for doing that for thank you for enduring. 01:08:33.347 --> 01:08:37.608 <v Wojciech Wegrzynski>That thank you for being here and yeah. 01:08:37.637 --> 01:08:39.318 <v Wojciech Wegrzynski>50 episodes of the podcast. 01:08:39.978 --> 01:08:42.347 <v Wojciech Wegrzynski>It makes me very happy and I hope. 01:08:42.768 --> 01:08:45.768 <v Wojciech Wegrzynski>You enjoy this show as much as I do. 01:08:46.278 --> 01:08:51.768 <v Wojciech Wegrzynski>And if you do well next Wednesday, next time I see you episode 51 and it's going to be. 01:08:51.828 --> 01:08:52.158 <v Wojciech Wegrzynski>Awesome. 01:08:52.427 --> 01:08:53.207 <v Wojciech Wegrzynski>As usual. 01:08:53.927 --> 01:08:54.677 <v Wojciech Wegrzynski>See you there. 01:08:54.768 --> 01:08:55.217 <v Wojciech Wegrzynski>Thank you. 01:08:55.247 --> 01:08:55.818 <v Wojciech Wegrzynski>Cheers.

050 - Wind, fire and a surprise

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