Automatic mesh generator for urban Computational Fluid Dynamics simulations

Despite the well-known potential of Computational Fluid Dynamics (CFD) to enhance the prediction of Building Performance Simulation (BPS) models, several barriers prevent BPS simulators from actively using CFD. A recognized obstacle is the proficiency required to get a high-quality computational mesh to study the atmospheric boundary layer (ABL) flow in actual urban environments. Hence, this work aims to present and validate an automatic tool to generate and discretize a virtual wind tunnel from an urban geometry model given as an input. The development comprises an unattended procedure that analyzes the buildings and their components (walls, openings, shadings), determines dimensions of the domain and grid refinements that abide by the best practice
guidelines, and finally constructs the mesh. Case studies with isolated and non-isolated buildings show the robustness and capabilities of the developed tool. A mesh convergence study is carried out to assess the sufficiency of the spatial discretization for ABL simulations.