Modelling of Fire Whirls

Fire whirls can occur in urban fires, especially those involving combustible building structures. They are aspecial swirling diffusion flame characterized by significant enhancement in burning rates, flame heights andflame temperatures, along with a strong whirling motion of the flame. This whirling motion can pick up largefirebrands and scatter them afar thus leading to rapid fire spread. Thus, fire whirls can cause significant loss toboth life and property.Martec is a leading Canadian engineering firm specializing in advanced engineering simulation technologyfor the design and analysis of complex structures and systems including fire and explosion modelling.Currently, Martec is interested in using appropriate sub-models for simulating fire spread in urban settings.Furthermore, Martec wants to ensure that the results obtained from these simulations will be accurate enoughfor the development of practical emergency measures, specification of safe set back distances from buildingfires, and formulating appropriate evacuation routes for different urban fire scenarios.This research proposal aims to undertake a comprehensive review of the literature on fire whirls, identifyinggaps in knowledge, evaluating the different models, and compiling a "roadmap" of the most promising modelsthat may be used and under what circumstances they may be incorporated as sub-models in a morecomprehensive fire spread code. A simple apparatus to investigate the behaviour of fire whirls will be designedand built. A series of experiments on fire whirls, comprising gas flames, liquid pools, and solid structures, toelucidate the criteria for onset of the fire whirl behaviour from the normal buoyant fire plume will beundertaken. The data from these experiments will be used to validate appropriate models identified in thecritical literature review, enhance or modify them if found inadequate, and/or used to develop new modelswhere existing ones are found to be inadequate.