Estimation of the Rate of Heat Release and Induced Wind Field in a Large Scale Fire

摘要

Logging slash on a 486 hectare site in Ontario was burned as part of a Forestry Canada forest management program. A 100 hectare portion of this site was instrumented by several groups interested in large scale fires. The NIST Center for Fire Research utilized Forestry Canada data on mass loading before and after the fire, total burning area as a function of time and burning duration to estimate the spatial and temporal pattern of heat release during the burning of the instrumented section of the fire. Complete information necessary for making this estimate is lacking; the necessary assumptions and their accuracy (when known) are discussed. Heat release rate is reported for three different assumptions regarding the temporal behavior of flaming and smoldering phases of the combustion. This information is utilized in the context of a flow model due to Baum and McCaffrey to calculate the near-ground flow field induced by this heat release pattern and the results are compared to the point measurements made in the field.