Can FDS predict flame spread accurately?
Flame spread and fire growth are difficult to predict for a number of reasons. First, there is often limited data to characterize the thermal and combustion properties of real materials. Second, flame spread often occurs on length scales below the resolution limits of a given calculation. In some cases, creeping flame spread can only be seen on numerical grids of roughly 1 mm resolution, but in many cases, reasonable flame spread can be predicted on furnishings with grid cells on the order of 10 cm. It is the responsibility of the modeler to understand the physical mechanisms employed by FDS to predict flame spread. Descriptions can be found in the Technical Reference Guide under Documentation. Assuming the physical model is adequate, the modeler must then ensure that FDS is predicting flame spread to whatever level of accuracy by comparing the computed results against experimental data. There have been some studies at NIST and elsewhere, but often the scenarios in the studies are much
