Unsteady free convection in cavity due to prescribed fluxes of heat or mass at the vertical walls.

Authors: Bark, F.H., Alavyoon, F., Dahlkild, A. A.
Document Type: Article
Pubstate: Published
Journal: J. Fluid Mech.
Volume: 235   665
Year: 1992


The accuracy and efficiency of numerical calculations of turbulent reacting flows past bluff bodies have been studied. The Reynolds-averaged Navier-Stokes equations, together with a two-equation k- epsilon model and a premixed flame model, are solved using finite differences on a system of global and locally refined grids. To improve the calculation efficiency, a multigrid (MG) method is employed. The influence of the grid resolution on the solution accuracy and the effects of the model parameters, boundary conditions and different reaction mechanisms are studied numerically. Comparisons are made between predictions and measurements of propane-air reacting flow past a bluff body placed in a wind tunnel. The computational time can be reduced considerably using an MG method, and the numerical accuracy can be maintained economically by using a local grid refinement technique. With proper model parameters, the solution of the simplified mathematical models is in good agreement with the experimental data.