Abstract
A new efficient method for conducting 3-D numerical simulations of turbulent airflow in and around buildings has been developed using composite grid system. The method can be applied to flow fields around buildings for any wind directions. The method uses the κ-εmodel as the turbulence model and the governing equations are discretized using a semi-staggaerd scheme on a semi:structured grid arrangement. The composite grid technique, which connects two or more grids in any overlapping style, is adopted here. A fortified solution algorithm, which connects dependent variables smoothly on each connecting region, was adopted in order to connect the coarse and fine grids. The coarse grid covers the whole computational domain while the fine grids recover important sub-domains on the coarse grid. This paper presents the numerical formulation and the connection methods of the composite grid system for the numerical simulations of airflow. In terms of applicability, the method promisses to be a useful and. accurate numerical simulations tool in the field of building aerodynamics and environmental-control engineering.
