ABSTRACT
The model presented joins the fire propagation equations in a 2D domain
representing the surface where the fire takes place, and the air movement
equations in a 3D domain representing the air layer above where the air
movements occurs. As the air layer thickness is small compared with its
length, an asymptotic analysis gives a 3D convective model governed by a 2D
equation verified by a stream function.
The model presented provides a 3D velocity wind field in the air layer under
the influence of the fire but it is governed by a 2D equation, so the it can
be coupled with 2D fire spread simulation models, taking into account two of
the most relevant factors for the spread of a fire: the wind and the slope.
The model is completed with some numerical examples.