FIRE-DRIVEN FLOWS IN ENCLOSURES

A two-dimensional Boussinesq model describing heat-driven, buoyant con vection in a polygonal enclosure is presented. The hydrodynamic model is based on the time-dependent Navier-Stokes equations with constant v iscosity and thermal conductivity; no turbulence model or other empiri cal parameters are introduced. The polygonal domain is mapped via a nu merical Schwarz-Christoffel transformation onto a rectangle, where the equations of motion are written in terms of the vorticity and stream function. An alternating direction implicit (ADI) difference scheme, s econd-order in space and first-order in time, is used to integrate the evolution equations, and a standard elliptic solver is used to solve the Poisson equation for the stream function. Computational results wh ich are of interest to the fire research community are presented.