Scale modeling of quasi-steady wood crib fires in enclosures

A scale modeling hypothesis for quasi-steady enclosure fires has been experimentally evaluated. The scheme utilizes geometric similarity and freeburn behavior of the source fuel to scale the source fuel element and the enclosure walls from one scale to another. The burning rate, gas and wall temperature rise, combustion product concentrations and radiative heat flux were measured in full, half and quarter-scale enclosures using wood cribs as the fuel. The good agreement of reduced data among different size enclosures strongly supported the modeling hypothesis. Relatively large scatters were observed with combustion product concentrations and radiative heat flux. In general, the scatters for the measured burning rate and gas and wall temperature rise in enclosure fires were within those observed in freeburn crib fires. The experimental results established that the modeling scheme can be used for predicting the burning rate and room environment in enclosure fires.