Stabilized finite element methods to predict ventilation efficiency and thermal comfort in buildings

The non-isothermal. incompressible Navier-Stokes equations with Boussineq approximation are considered as a model of turbulent indoor air flows. The transient calculation is based on the Reynolds-averaged Navier-Stokes problem L[Sing the k/epsilon-turbulence model or improved variants such as the (upsilon) over bar (2)-f model. The model is first discretized in time using backward-differencing schemes and then linearized using a Newton-type method per time step with emphasis on the proper calculation of (non-negative) turbulence quantities. The resulting auxiliary problems of Oseen type and of advection-diffusion-reaction type are solved Using stabilized finite element method of residual type. Here we summarize Some some of our recent analytical results for hi I'll er-Order methods and shock-capturing techniques. The numerical solution to the model in boundary layer regions is obtained using either adaptive wall functions if the k-epsilon model is Used or a hybrid mesh with anisotropic refinement if the (upsilon) over bar (2)-f model is applied. Besides the standard flow quantities, it is possible to calculate quantities such as the age of the air. Such quantities are Used to develop criteria for the evaluation of the efficiency of air exchange in a room. The quality of the numerical simulations is demonstrated for typical benchmark problems. Copyright (C) 2008 John Wiley & Sons, Ltd.