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"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)----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.