Radiative heat transfer from multiple discrete fires

The behavior of multiple discrete fires is often different from that of a single fire. Because of the interaction among these fires, their burning rates and flame lengths can increase. Also, the increasing radiative heat transfer from multiple flames is partially responsible for the remote ignition and accelerated flame spread in large-scale urban and wildland fires. To understand the distribution of radiant heat fluxes from multiple discrete fires, experiments have been performed with an array of individual pool fires of variable spacing and size. Results show that a point-source radiation model can be extended from a single pool fire to the array of discrete pool fires. The analysis shows that the radiative heat flux from the fire array was proportional to the fuel–area ratio (or the fuel surface density) and was inversely proportional to the square of the distance to fire array. This work quantifies the role of radiative heat transfer from large-scale discrete fires, thus helps understand the extreme fire behaviors in large-scale urban and wildland fires.