An Integral Model for Wood Auto-ignition under Variable Heat Flux

A one-dimensional integral model that predicts the auto-ignition time of wood under linearly increasing radiant heat flux is developed. The solution to the integral model for the ignition time is compared with measured data. Reasonable comparative results are shown for the ignition time of wood exposed to different heat flux increase rates (HFIR). Both the solutions and the measured data also show that the ignition time can be expressed as a power function and the power exponent is about 0.67.