We are living in a kind of weird time, where the most complex tool we have is at the same time the most commonly used (and abused one). The Computational Fluid Dynamics (CFD) modelling has brought us amazing capabilities in solving the flows within fires. But this power comes at a price - knowledge, resources, time... Sometimes we lack some of these (or all) and we turn the power tool into a generator of beautiful images that are hardly any representation of the physics of the fire...In this episode with Dr Wolfram Jahn, we go deep into the application of the CFD in fire science and engineering, searching for the boundary at which the CFD stops being the right tool for the job. From the evolution of our models, through the choice of meshes and boundary conditions, up to the workflow of the CFD modelling, we touch the important choices the engineers do every day. Focusing on the practical side of the issue, we try to figure out the best advice we can give to the engineers, on how to use the CFD in the most reliable (and correct) way.Connect with Wolfram Jahn at:LinkedIn - https://www.linkedin.com/in/wolframjahn/Twitter - https://twitter.com/wolfrisResearchGate - https://www.researchgate.net/profile/Wolfram-Jahn-2--- LinkedIn Discussion thread ---https://www.linkedin.com/posts/fire-science-show_episode-13-on-the-use-and-abuse-of-cfd-activity-6831120537499025408--nvl--- Usefull links ---FDS download (make sure to check the example cases and the Verification & Validation guide!!!) - https://pages.nist.gov/fds-smv/downloads.htmlBenjamin Ralph on V&V of FDShttps://www.youtube.com/watch?v=ipnGrAeG5zwSummer School on FDS modelling at Juelich Forszungszentrum https://www.fz-juelich.de/ias/ias-7/EN/Research/Fire_Dynamics/Events/SummerSchool2019/_node.htmlDalmarnock paper (simulations before the experiment) - https://www.sciencedirect.com/science/article/pii/S0379711209000034?via%3DihubDalmarnock paper (simulations after the experiment) -  https://www.sciencedirect.com/science/article/pii/S036013231000332X?via%3Dihub50 years of Computational Wind Engineering - a view on the world of the CFD through a wind engineering eyes - https://www.sciencedirect.com/science/article/pii/S016761051400052XWegrzynski & Tofiło - Hand calculations, zone models and CFD – areas of disagreement and limits of application in practical fire protection engineering @ SFPE Warsaw 2016 https://www.researchgate.net/publication/305808429_Hand_calculations_zone_models_and_CFD_-_areas_of_disagreement_and_limits_of_application_in_practical_fire_protection_engineering