Exam CFPS Topic 1 Question 26 Discussion

Explanation
The two classes of fire models arephysical and mathematical. Physical fire models are scaled-down representations of real fire scenarios, using laboratory experiments and measurements to study the fire behavior and effects.Physical fire models can be used to test hypotheses, validate mathematical models, and provide empirical data for fire analysis1. Mathematical fire models are numerical or analytical solutions of the equations that govern the fire phenomena, such as heat transfer, fluid dynamics, combustion, and chemical kinetics.Mathematical fire models can be used to simulate fire scenarios, predict fire outcomes, and optimize fire protection systems2. There are two major categories of mathematical fire models: zone models and field models. Zone models divide the fire compartment into two or more homogeneous zones, such as upper and lower layers, and apply mass and energy conservation equations to each zone.Zone models are relatively simple, fast, and easy to use, but they have limitations in accuracy and applicability3. Field models solve the partial differential equations that describe the fire-driven fluid flow and heat transfer in three dimensions, using computational fluid dynamics (CFD) techniques.Field models are more detailed, realistic, and flexible, but they require more computational resources and expertise4.References:
Fire modelling with Computational Fluid Dynamics - BRE Group
Fire modeling programs | NIST
interFIRE, A site dedicated to improving fire investigation worldwide.
Computer Fire Models for Fire Investigation and Reconstruction