Modelling ignition and fire of a tree branch with some leaves can't be that much different from modelling burning timber, right? Well, that is the kind of ignorance that can backfire on you... It certainly did on me! I have honestly not imagined how complicated fires of living (and dead) vegetation may be. How different heat transfer phenomena will have the leading impact (convective heating and cooling!) and how some of the assumptions I'm very used to may be useless. I guess I should have paid more attention to the episodes with Sara McAllister and Mike Gollner!Anyway, today I'm treating my ignorance with the best cure I know - talking to an expert, who really knows his craft. This guest is Dr Eric Mueller from NIST, who has done his PhD at Edinburgh on modelling natural fuels, and now continues this research at NIST. Eric is responsible not only for researching this field, but also implementing and improving models and routines of FDS that relate to natural fuels. As such, he is a priceless knowledge resource. In this episode, you will learn a lot about convective heat transfer, porosities and drag coefficients - some concepts that were a little alien to me before... at least not at the level of importance that I would assign to them now. So if you feel you may learn this and that about burning living fuels, please join me in this episode. And if you feel it is useless... well yeah, thought the same and got reality checked pretty hard on this! If you somehow missed it, make sure to check the video from IAFSS20 where Eric received the best thesis award, and astonished everyone with his magnificent presentation. It is available here: https://www.youtube.com/watch?v=EHif1bh5o2g