2010 Volume 60 Issue 3 Pages 39-46
Database currently being applied to the fire modeling has been mostly based on the data on free burning. It means that the free burning data may result in under-predict of fire propagation and smoke toxicity. In fact, oxygen and thermal condition within a compartment fire is unsteady. Therefore, growth, flashover, fully-developed and decay period fire data is actually necessary depending on which period the fire research investigates. Fire data should be experimentally measured and input into the database to reconstruct the fire scene as many as possible. Time to ignition, mass loss rate, yields of carbon monoxide (CO) and carbon dioxide (CO2) of Douglas fir for each grain direction depended on the thermal and oxygen condition (XO2(volume fraction of oxygen) = 21-12.5 vol% and Φ (equivalence ratio) = 0 - 0.3) were investigated using the small scale Universal Flammability Apparatus (UFA) which reproduce thermal and oxygen condition in a compartment. Time to ignition of across the grain is twice as much as the one of along the grain. This is attributed to the difference of thermal conductivity for each grain direction. Mass loss rate of Douglas fir shows char layer above live Douglas fir relative to PMMA controls radiation feedback from flame to the fuel surface. Carbon monoxide yield as a function of oxygen concentration and equivalence ratio is different for across and along the grain as well as time to ignition.
