User must thoroughly understand fire model
Paul Sincaglia
Firefighter/Investigator
Chagrin Falls (OH) Fire Department
I would like to applaud Fire Engineering for publishing James Shanley`s articles (January, May, and June 1994) and making the fire service community more aware of the existence of and uses for computer fire simulation. This tool, in the hands of a competent professional, can be used not only to recreate fire development as outlined in this article but also to develop fire scenarios for existing structures for use in a preplan or training exercise.
As Shanley mentioned, the fire model is a very sophisticated tool based on fundamental physics and experimental results. Therefore, the user must thoroughly understand numerous conditions (boundary limits, assumptions, etc.) prior to using the model–for example, all of the models he mentioned are based on the assumption that the fire begins with strong, flaming combustion. If the fire being reconstructed had been small or smoldering for an extended period, the gas concentrations (oxygen, carbon dioxide, carbon monoxide, etc.) in the room of origin may significantly affect fire development and/or the toxicity of adjacent rooms.
The point is that, even though the models themselves are readily available, if the user does not have a firm understanding of the physics, thermodynamics, and chemistry utilized by the model, the user is likely to obtain numerical results that are significantly in error. As Shanley states, “Garbage in equals garbage out.”
