plume_rise_1.fds from the FDS Validation Guide (by NIST)

&HEAD CHID='plume_rise_1',  TITLE='Test plume rise height in stable atmosphere' /

&MESH IJK=50,52,50, XB=-50.,50.,-52.,52.,0.,100., MULT_ID='mesh1' /
&MULT ID='mesh1', DZ=100., K_UPPER=1 /
&MESH IJK=50,52,50, XB= 50.,250.,-104.,104.,0.,200., MULT_ID='mesh2' /
&MULT ID='mesh2', DZ=200., K_UPPER=1 /
&MESH IJK=50,50,50, XB=250.,650.,-200.,200.,0.,400., MULT_ID='mesh3' /
&MULT ID='mesh3', DX=400., DZ=400., I_UPPER=3, K_UPPER=1 /

&TIME T_END=900. /

&MISC TMPA=20.36 /

&WIND SPEED=5., LAPSE_RATE=-0.0048 /

&SPEC ID='SULFUR DIOXIDE' /

&VENT MB='XMIN', SURF_ID='OPEN' /
&VENT MB='XMAX', SURF_ID='OPEN' /
&VENT MB='YMIN', SURF_ID='OPEN' /
&VENT MB='YMAX', SURF_ID='OPEN' /
&VENT MB='ZMAX', SURF_ID='OPEN' /

&PART ID='TRACERS', MASSLESS=.TRUE., SAMPLING_FACTOR=1 /

&SURF ID='TOP', TMP_FRONT=200., MASS_FLUX(1)=0.01563, SPEC_ID(1)='SULFUR DIOXIDE', MASS_FLUX(2)=18.85, SPEC_ID(2)='AIR', COLOR='BLACK', PART_ID='TRACERS' /

&OBST XB=-2.0,2.0,-2.0,2.0, 0,75, SURF_IDS='TOP','INERT','INERT' /

&SLCF PBY=0, QUANTITY='VELOCITY', VECTOR=.TRUE. /
&SLCF PBY=0, QUANTITY='TEMPERATURE' /
&SLCF PBY=0, QUANTITY='DENSITY' /
&SLCF PBY=0, QUANTITY='MASS FRACTION', SPEC_ID='SULFUR DIOXIDE' /

&DEVC ID='z_CL', QUANTITY='MASS FRACTION', SPEC_ID='SULFUR DIOXIDE', XB=1800,1850,-200,200,0,800, SPATIAL_STATISTIC='MAXLOC Z' /

&TAIL /

Thank you NIST for providing an endless source of ASMR scripts on your github here: https://github.com/firemodels/fds/tree/master/Validation

I recommend everyone to go through this rich resource.

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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.

When one takes a decision to evacuate and starts moving, this is not the end of their decision-making process. 

Which route to take? Who to contact? How to arrange a place of shelter? Where to go first? Have I forgotten anything? 

I previously discussed the decision-making with Erica Kuligowski from RMIT, and today we're meeting again to follow up on decision-making for large-scale evacuations. We focus on choices and uncertainties that make many of the evacuees take additional trips, and those trips become background traffic that interferes with your escape. In this episode, we dive deep into the decision making in this stage, the sources of data, and hypothesise how this knowledge could be used in practice.

And of course, Erica being one of the leaders of the Human Behaviour in Fire community gives us a high level overview how this part of science looks like, and what is currently being researched.

The HBiF conference we mentioned in the episode can be found here: https://humanbehaviourinfires.se/

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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.

A fire in an informal settlement is not just another small building fire. It can be the first domino in a fast-moving neighborhood event, and the little details like the wall material, roof material, door location, even a light breeze, can decide what happens next. I’m joined by Dr. Sam Stevens from Kindling to unpack a massive FSRI funded experimental program carried out in South Africa that burned twenty different informal and humanitarian shelter types to measure real heat flux, flame extension, and fire spread potential. 

We start repeating the uncomfortable gap: humanitarian guidance often relies on rules of thumb like a universal separation distance and vague advice to “use fire-resistant materials,” with little experimental evidence behind it. Sam explains how Kindling built a global database of shelter designs and materials, then narrowed it down to common typologies spanning sheet metal, mud, timber, bamboo mats, split bamboo, thatch, and tarpaulin tents. We dig into the field-scale test setup, why wood cribs were chosen, and how external instrumentation like thin skin calorimeters helps quantify the heat transfer that drives structure-to-structure ignition. 

Then we get into what the burns actually show. Non-combustible shelters often behave like classic compartment fires where openings dominate, but even modest wind can push flames meters outward. Add combustible walls or roofs and the hazard shifts dramatically: some materials produce short, intense exposure windows while others sustain burning long enough to threaten neighbors at greater distances. The fully thatched shelter stands out for extreme radiant heat and duration, and our discussion on tarpaulin tents reveals why common fire test methods can produce reassuring ratings that still miss real-world behavior. 

If you care about informal settlement fire safety, humanitarian shelter design, fire engineering guidance, or modeling large outdoor fires in dense communities, this conversation gives you a data-driven foundation and a clear sense of what questions still need answering. 

Learn more about the project and watch their educational videos here: https://kindlingsafety.org/projects/large-scale-fire-experiments-for-humanitarian-shelters/

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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.

Being a part of broader civil engineering and built environment sciences, we have the unique opportunity to learn from other "sister" disciplines, rather than coming up with everything on our own. Especially, when those disciplines have 100+ years of experience in investigating stuff that has recently emerged as one of the leading challenges in our field.

The other discipline is Earthquake Engineering.

The interesting stuff - community resilience and managing safety across tens of thousands of buildings exposed to the same hazard.

Our field of application - Fire Safety of WUI communitites.

And most importantly, my diligent guests: Negar Elhami-Khorasani from University at Buffalo, and Justin Moresco from Applied Technology Council.

In this episode we discuss how earthquake engineering deals with hazards through four steps: 

1. Hazard assessment, 
2. System response (exposure)
3. Damage assessment (vulnerability)
4. Level of loss (consequences)

You will learn what are fragility functions and how they are applied. We will also discuss building archetypes and how we can use them to increase or decrease the level of detail in our analysis.

If you want more:

• Conceptualizing a probabilistic risk and loss assessment framework for wildfires
• Toward Probabilistic Risk Assessment of Wildland–Urban Interface Communities for Wildfires

Recommended follow-up podcast episodes:

• 156 - Trigger Boundaries with Harry Mitchell and Nick Kalogeropoulos
• 215 - Lessons from the 2018 Camp Fire with Eric D. Link
• 222 - Integrating WUI risk management and fire safety engineering with Pascale Vacca

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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.

Is it too late to start with the AI in 2026? It wen't so far, does it still make sense to get interested in this technology?

Absolutely. Today we sit down with MZ Naser of Clemson University to map a clear, useful path for engineers who want results without the hype. We start with the basics - clean data, the right algorithm, and a realistic mindset - and climb toward explainability, causality, and even philosophy to show where AI informs decisions and where it can quietly mislead.

We dig into the limits of our experiments: when tests are expensive, we control only a few variables and then celebrate when explainable AI “finds” the same drivers. That’s not discovery; that’s confirmation. MZ explains how broader sampling, anomaly detection, and careful clustering can reveal patterns we miss, while acknowledging that physics is fixed but our datasets are narrow. We also talk scale: a model that predicts whole-building fire behavior from scratch is a fantasy without impossible data. The practical play is combining reasoning, physics, and simulation to guide where AI adds value - sometimes leading to a simpler equation that replaces the model altogether.

Then we get tactical. What is agentic AI, and how can it save engineers real time? Think delegated workflows: data gathering, parametric setup, code lookups, Excel design sheets, quality checks, and concise summaries. Train agents with explicit steps and tight guardrails, keep them away from money and safety-critical controls, and make human review mandatory. We also confront traceability and model retirement - why freezing working versions, documenting assumptions, and cross-verifying with independent methods matter for audits years down the line.

Throughout, we balance open local models versus cloud LLMs, the trade-offs between control and convenience, and the hard truth that black boxes don’t absolve us of understanding. The big takeaway: AI is a lever, not a miracle. Use it to widen your view, automate routine work, and challenge your priors - while keeping physics, data quality, and professional judgment at the center.

If this conversation helps you think clearer about where AI fits in your workflow, follow the show, share it with a colleague, and leave a quick review so more engineers can find it.

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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.

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

Update: A week later there has been a lot of works that have refuted the dark scenario in Citrini piece, like here: https://www.businessinsider.com/ai-job-losses-wall-street-strategist-citrini-research-citadel-securities-2026-2?IR=T

Some are showing Software Engineering job openings rising etc. Perhaps world is not in the dark scenario - I highly hope so! 

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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.

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

Numerical modeling of the fire behavior of reinforced concrete tunnel slabs during heating and cooling

Fire Damage Assessment of Reinforced Concrete Tunnel Linings

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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.

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"
• 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" - (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"
• Episode 100 - Smoke plumes! That was a fun one.
• G. Heskestad "Fire Plumes, Flame Height, and Air Entrainment" from SFPE Handbook  (also the source of the overlayed image on the cover showing range at which fires exist)

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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.

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

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
• 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/

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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.

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?

- Transient characteristic of the flow of heat and mass in a fire as the basis for an optimised solution for smoke exhaust

- Smart Smoke Control as an Efficient Solution for Smoke Ventilation in Converted Cellars of Historic Buildings

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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.