AUTOMATIC MESH GENERATION FOR FEM SIMULATION OF WIND FLOW AROUND TALL BUILDINGS

In this paper, we present efficient fully automatic generation algorism of 2D triangular and 3D tetrahedral FEM mesh with arbitrary mesh size control. In the first step, relatively coarse mesh with small number of elements is generated. Then recursive local subdivision is performed until all elements satisfy the requested mesh size distribution. We also present local element conversion algorism from triangular and tetrahedral mesh. Unstructured 2D quadrangular(3D hexahedral) mesh with arbitrary grid density distribution is generated automatically by simple conversion procedure from triangular(tetrahedral) mesh. Using our method, 3D wind flow in actual model cases are computed using FEM solver and good results are shown.