Calculations of Three Dimensional Buoyant Plumes in Enclosures

A computational model of the three-dimensional buoyant convection and aerosol dynamics induced by a weak volumetric source of heat and mass is presented. The hydrodynamics is directly based on the time-dependent inviscid Boussinesq equations. No turbulence model or other empirical parameters are introduced. The use of Lagrangian particle tracking together with an exact solution of the Smoluchowski equation allows prediction of smoke aerosol transport and coagulation. The combined calculations represent predictions involving five independent variables. Flow features from three different configurations are illustrated with both Eulerian and Lagrangian displays of information. Sample aerosol coagulation results are compared with data reported from a wood fire. The computer resources required are discussed, and an assessment of the current feasibility of large-eddy simulations in fire research is made.