Fire Safety Science Digital Archive

The winds generated at 11:45 a.m. by 38 fires and at 12:00 p.m. by 259 fires for the 20 October 1991 Oakland Hills Fire are simulated using the Baum and McCaffrey mass fire model. Each house is modeled as having a 50 MW heat release rate at the time of the computation. For each single fire, the flame tip is 15 m high, the maximum vertical velocity is 16 m/s and the maximum radial velocity is 2.4 m/s. At 11:45 a.m., for the mass fire the maximum induced wind is 2.6 m/s. The maximum vertical velocity is 14 m/s. At 12:00 p.m., the maximum horizontal velocity is 13 m/s. The maximum vertical velocity is 2.6 m/s. Results indicate that the strong fire-induced winds at and after 12:00 p.m. contributed to the post-noon decrease in the fire spread rate in the ambient windward direction.