Fire Science Show

240 - Distressed by the AI stuff around

I’m not stressed by AI itself. I’m stressed by the insatiable greed of those who profit from it, even if it means sacrificing large parts of the population. I'm also stressed about how ruthlessly it can be abused to cause deliberate harm. In this episode I'm not taking you into world of fire science, but rather into my own thoughts on how the AI revolution influences our lives. And I was influenced it just last week - through a phishing attack on the IAFSS, and through reading a very disturbing piece of fiction I found on the Internet... In the episode I comment on the targeted phishing attack against our association that used well-researched details and a cloned voice pulled from public audio. From there, we step into a stark forecast of near-term AI disruption in white-collar work. Agent teams can already write, review, and ship production code in loops, compressing time and cost while jolting stock prices across entire sectors the moment capabilities drop.  Then we get specific about our field. Some tasks in fire safety are ripe for automation—code interpretation, routine calculations, device placement, and documentation—where speed and consistency help. But holistic fire strategy is contextual and slow to validate, with scarce, standardized case data and long feedback loops. Buildings are messy, multidisciplinary systems; that friction is a temporary moat against full automation. The larger risk may be macroeconomic: if AI compresses demand and margins across white-collar industries, construction cools, and safety work gets squeezed. Paradoxically, low digitalization in construction buys time, making it harder to train and deploy one-size-fits-all models. I'm still to large extent positive Fire Safety Engineering won't be directly disrupted at the same scale as Software Engineers got, but as a part of a larger ecosystem we won't be untouched either... I hope the version of the future that plays out is more optimistic than the one I got worried about. Read the Citrini piece here, if you have not yet: https://www.citriniresearch.com/p/2028gic ---- The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

239 - Assessing post-fire structural damage in tunnels with Negar Elhami-Khorasani

A tunnel can ride out a fire without collapsing (or even critical visible structural damage), but a question whether it is safe for operations, and what is its long-term residual fire resistance remains. With repair bills being in high seven-eight figures, this is more than just a theoretical question... In this episode we dig into the hard middle ground of fire damage post mild/large fires, and cover where modeling and fire science can help reducing the uncertainty and guiding decisions. With Professor Negar Elhami-Khorasani from University at Buffalo, we map how ventilation settings, tunnel slope, and fuel push temperatures into either safe or punishing regimes, and why spalling can turn a survivable event into a structural headache. We break spalling down to first principles—vapor pressure, thermal gradients, and restraint—then translate that into a practical method: update the section as concrete “disappears” so the thermal boundary moves and heat penetrates realistically. From there, we track damage you can act on: concrete volumes beyond 300°C, steel temperatures that risk incomplete recovery, and bond loss that forces major repairs. Just as important, we model through cooling, when heat keeps migrating and residual capacity sinks. The result isn’t a guess; it’s a bounded map of what to replace and why. We also take on the tactical questions that matter: How long would an extreme fire need to threaten collapse, given different soils and depths? What’s the real value of polypropylene fibers in high-strength mixes? How should owners structure a fast, post-fire workflow—quick checks for reopening within days, followed by a deeper, simulation-informed durability plan? By pairing observed spalling and known operations with targeted heat transfer and mechanical analysis, you can reconstruct the event, communicate risk clearly, and spend repair budgets where they return the most resilience. If you care about structural fire engineering, tunnel safety, spalling mitigation, and performance-based design that reduces downtime, this conversation delivers a roadmap you can use. Further reading - recommended papers by Negar Elhami-Khorasani and her team: Structural fire behavior of tunnel sections: assessing the effects of full burnout and spalling effects [https://www.scopus.com/pages/publications/105027854065?origin=resultslist] Numerical modeling of the fire behavior of reinforced concrete tunnel slabs during heating and cooling [https://www.scopus.com/pages/publications/85126391159?origin=resultslist] Fire Damage Assessment of Reinforced Concrete Tunnel Linings [https://www.scopus.com/pages/publications/85180772226?origin=resultslist] ---- The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

238 - Fire Fundamentals pt. 19 - Defining fires in your models

Welcome to another fire fundamentals episode! Today we dig into how to place a fire in a model so results reflect real physics. From plume inputs to FDS burners, we show where HRRPUA, radiative fraction, and D* make or break smoke your calculations. Things considered in this episode: • why defining the design HRR is separate from placing the source • what a flame is and why we cannot resolve its chemistry • plume models compared by inputs: perimeter, Q, Qc • entrainment, virtual origin, and effective diameter • realistic HRRPUA ranges for building-scale fires • radiative vs convective fractions and why they matter • zone model linkage to plumes for smoke control • volumetric smoke and heat sources for CFD: volume, placement, and limits • fuel-based fires in CFD and oxygen constraints • growth modeling via area expansion vs flux ramping • soot yields, heat of combustion, and visibility • D* and meshing guidance for credible resolution • why predictive fire spread modelling for design use does not really exist... Resources, resources! * G. Vigne et al. "Review and Validation of the current Smoke Plume Entrainment Models for Large-Volume Buildings" [https://spiral.imperial.ac.uk/server/api/core/bitstreams/ee215837-381f-4472-b504-9053733748c2/content] * W. Węgrzyński & M. Konecki "Influence of the fire location and the size of a compartment on the heat and smoke flow out of the compartment [https://www.researchgate.net/publication/319855580_Influence_of_the_fire_location_and_the_size_of_a_compartment_on_the_heat_and_smoke_flow_out_of_the_compartment]" - (this is a paper from my PhD where I explain the concept of volumetric heat source) * M. Bonner et al. "Visual Fire Power: An Algorithm for Measuring Heat Release Rate of Visible Flames in Camera Footage, with Applications in Facade Fire Experiments" [https://link.springer.com/article/10.1007/s10694-022-01341-z] * Episode 100 - Smoke plumes! [https://www.firescienceshow.com/100-fire-fundamentals-pt-3-smoke-plumes-and-other-flow-phenomena-with-wojciech/]That was a fun one. * G. Heskestad "Fire Plumes, Flame Height, and Air Entrainment" from SFPE Handbook [https://link.springer.com/chapter/10.1007/978-1-4939-2565-0_13] (also the source of the overlayed image on the cover showing range at which fires exist) ---- The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

237 - Fire Fundamentals pt. 18 - Explosions with Ali Rangwala and Lorenz Boeck

Welcome back to Fire Fundamentals! Today with prof. Ali Rangwala from WPI and dr Lorenz Boeck from Rembe and WPI we take the world of explosion protection engineering.  In this episode we touch: • distinguishing fires and explosions by time scale and damage mode • taxonomy of explosions by energy density and deposition time • hybrid mixtures in coal mines and turbulent burning velocity • severity metrics for gases and dust deflagration index for reactivity • explosion sphere testing, ignition positioning, and model limits • ignition sensitivity minimum ignition energy and hot surface risks • prevention via ventilation, inerting, and ignition control • protection through deflagration vents, isolation, and external hazards • pressure vessel bursts, inspections, and rupture disks • transport scenarios vapor clouds and BLEVEs with fireball correlations We also delve into future directions for explosion research: • emerging risks hydrogen, BESS, ammonia, and layered defenses • space and microgravity impacts on dust and flammability Check out the XPE programme at WPI, and find more informations on how to enroll at:  https://www.wpi.edu/academics/study/master-science-explosion-protection-engineering [https://www.wpi.edu/academics/study/master-science-explosion-protection-engineering] I have also received some good listening material, that you could follow up with: * A podcast done by Ali's PhD student, Hannah Murray and Prof. Stephen Kmiotek who is the co director of XPE. This was done by WPI and the link is : https://www.wpi.edu/listen/wpi-podcast/e18-explosion-protection-engineering-hannah-murray-explosion-protection-engineering-phd-candidate [https://www.wpi.edu/listen/wpi-podcast/e18-explosion-protection-engineering-hannah-murray-explosion-protection-engineering-phd-candidate] * There is one more podcast that was more focused on dust explosions. This was done by Dust Safety Science, by Chris Cloney and also explains the program. In this its Prof. Kmiotek and Ali: https://dustsafetyscience.com/explosion-protection-engineering-program/ [https://dustsafetyscience.com/explosion-protection-engineering-program/] ---- The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

236 - Fitting an efficient smoke control system in a confined space

A tight, historic cellar. Arched ceilings. Long corridors. Tiny shafts. We faced a design wall: to keep routes tenable, we needed twice the extraction that the building could carry. At that point, I've failed as an engineer - I've reached my limit and could not find a solution. Some time later, a solution appeared in my head from nowhere —what if the fan changed with the fire? Not in a crude on-off way, but by tracking temperature, exploiting density changes, and chasing constant mass flow instead of fixed volume. We unpack the moment this clicked, the fan physics behind it, and why hotter smoke can actually make extraction easier if you use the margin correctly. You’ll hear how we oversized the fan, ran it at a lower frequency in ambient, then ramped as temperatures rose to keep kilograms per second steady. That adaptive control boosted cubic meters per second right when the layer needed support, eased plug-hole entrainment, and stabilised makeup air velocities. We walk through the thermodynamics, the electrical and pressure implications, and how these pieces form a practical control strategy for retrofits and new builds. To ground the idea, we share two paths to proof. First, CFD with user-defined control that reads gas temperature each time step and updates fan frequency with smoothed delays to prevent oscillations—capturing the real feedback loop between fire and system. Then, full-scale container burns with live control showed the same trends from 20 to over 500 degrees: falling duct pressures, lower fan power at heat, and the headroom to increase volumetric extraction without breaking limits.  Thinking about it now, this idea is a part of many other concepts that I describe together. To show a way how we come from the simple framework—Smoke Control 1.0 (empirical, static), 2.0 (CFD-informed, still static), into a new smoke control 3.0 (adaptive, feedback-driven)—and explore how this thinking can reshape underground venues, car parks, tunnels, pressurisation, and natural ventilation. If you care about safer evacuation, smaller shafts, lower velocities, and systems that work with physics rather than against it, this story is for you. Subscribe, share with a colleague who designs smoke control, and leave a review with your toughest question so we can tackle it next. Reading material: - Can smoke control become smart? [https://doi.org/10.2478/ace-2018-0040] - Transient characteristic of the flow of heat and mass in a fire as the basis for an optimised solution for smoke exhaust [https://www.sciencedirect.com/science/article/abs/pii/S0017931017318203?via%3Dihub] - Smart Smoke Control as an Efficient Solution for Smoke Ventilation in Converted Cellars of Historic Buildings [https://www.scopus.com/pages/publications/85091370204?origin=resultslist] ---- The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.