Fire Safety Science Digital Archive

Based on energy conservation and detailed heat transfer mechanisms, a simple physical model for fire spread is presented for the limit of one-dimensional steady-state contiguous spread of a line fire in a thermally-thin uniform porous fuel bed. The solution for the fire spread rate is found as an eigenvalue from this model with appropriate boundary conditions through a fourth order Runge-Kutta method. Three experiments on fire spread are compared to the model simulations and good agreement is demonstrated. The comparisons with wind tunnel experiments on white birch fuel beds show that the physics in this model successfully evaluates wind and slope effects on the fire spread rate. The grassland fuel experiments with various fuel characteristics also compare well to the simulations. Limited comparison with data on fire spread in shrubs, obtained in China, also shows good agreement. These comparisons suggest that this model may serve as the basis for an improved operational model.