In this episode of Fire Fundamentals, together with Dr Sara McAllister, we dwell on how stuff burns... And it is far from an easy question. While the general theme of the episodes is porous fuels, we discuss them from different angles, highlighting the similarities and differences between foamed and permeable materials.

In this episode, we cover:

• role of permeability, entrainment and forced flows through porous fuel beds;
• differences in physical properties between porous materials and their bulk forms;
• ignition (flaming and smouldering) of porous fuels;
• natural and artificial fuels, open and closed cell fuels;
• hazards specific to porous fuels in wildfires and in building fires;

And also a bit of discussion on future research of Dr McAllister along with the need for canonical tests to characterize their flammabaility.

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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.

Can a tiny amount of bio-protective coating completely change the fire behaviour of mass timber logs? If you asked me that some time ago, I would say it would probably be neutral.

Can a 0.5 x 0.5 m free-standing log of timber smoulder through without any external exposure to fire? If you asked me that some time ago, I would say no, and base that on observations of dozens of logs like this.

Yet, in Australia they’ve burned. And the hypothesis was that it has something to do with the preservative treatment.

My guest today, Wenxuan Wu from The University of Queensland was tasked with researching this problem and showed us the workshop used for this. In this podcast episode, we dive deep into measurements carried out in fire laboratories on the material scale and how use of different methods gradually increases our understanding of the problem. Their pursuit also opened new questsions - for example, why if timber would be subject to a very strong heat flux, the smouldering would not work anymore? This was also answered in the discussion.

If you would like to learn more about Wenxuan’s research, please refer to the published papers:

• Experimental study on the factors affecting smouldering behaviour of CCA-treated wood
• Deactivation of chromated copper arsenate as a catalyst in smouldering of wood

Also, this talk summarises the best poster at ITB-FRISSBE Summer School. What an event that was. Once again, we would like to thank our sponsors for that!

https://www.itb.pl/2024-summer-school/

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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.

If we truly want to account for the population at a disadvantage in evacuation, there is only this much we can do with the current approach... Pre-evacuation time distributions, walking speeds, and so on only tell us a part of the story - the story of your average person within an average population, with an average walking speed and average response. While these models are undoubtedly useful in engineering, there is perhaps a better way.

My friend and guest Enrico Ronchi is trying to find this way through his new ERC Consolidator grant, "Egressibility: a paradigm shift in evacuation research". In this grant, instead of following the main path, he is focusing on stuff we do not know - how to characterise disabilities and understand them better (also through the lens of health and medicine), how to quantify the disadvantages at large, and how to solve potential issues for those who those at the largest risk.

In this episode, you will learn about Enrico's ideas and the edge of the knowledge we have today. Some key points covered are:

• Insights on paradigm shifts in evacuation science
• Introduction of the concept of "egressibility"
• Importance of understanding functional limitations in emergencies
• Shift from agent-based models to inclusive data-driven models
• Use of technology, like VR, for immersive research experiences
• Need for changes in regulations for better evacuation safety

You may also like to read the paper by Guylène Proulx, which introduced egressibility as a concept - available here.

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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.