https://firelab.berkeley.edu/ this is the place you need to go!

Ignition at different slope angles. Firebrand spotting. Fire whirls. What does connect these various fire phenomena? They are all driven by fluid dynamics and can happen only in very particular flow conditions. To define and understand these conditions... well that is a bit longer story that I will unravel with Prof. Michael J. Gollner of the University of California, Berkeley.

In Episode 14 we have gone on a journey through scales of the fire phenomena with Sara McAllister (USDA).  Today's episode is in a way follow up to that journey, as with Michael we try to understand why slope angle is such an important variable in the ignition of solids (and why peakHRR is not necessarily at the same slope as peak fire spread!).  We venture into wind-driven crown fires and ember generation within them. Finally, we discuss the fire whirls, and notably - Michaels team discovery of "blue fire whirl" during his time in UMD. Although the topics seem very fundamental, we stay in touch with engineering... In the end, the influence of slope angle on the flame spread is interesting, and at the same time fundamental to predicting wildfire spread. Firebrand aerodynamics is fascinating, but if we don't understand that, we won't be able to build homes resilient to wildfires. Blue whirl is beautiful, but one day it may be the answer to efficient cleaning of oil spills. This episode is full of fantastic fire science, for everyone!

Connect with Michael on Twitter and LinkedIn

Check the collection of resources for fire protection engineers on Firelab Berkeley website.

Read up on Michaels research:

• Studies on upward flame spread (PhD Thesis at UCSD)
• M Finney et. al. Role of buoyant flame dynamics in wildfire spread PNAS
• A Tohidi, MJ Gollner, H Xiao, Flame Whirls Annual Review of Fluid Mechanics
• H Xiao, MJ Gollner, ES Oran, From fire whirls to blue whirls and combustion with reduced pollution PNAS

Thank you to the SFPE for recognizing me with the 2025 SFPE Fire Safety Engineering Award! Huge thanks to YOU for being a part of this, and big thanks to the OFR for supporting me over the years.

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