From One-Month CFD to One-Day CFD: Efforts for Reducing Time and Cost of CFD

摘要

This paper discusses our effort to develop a versatile and efficient CFD system, named TAS-code (Tohoku University Aerodynamic Simulation Code). The TAS code consists of several modules; surface mesh generation, tetrahe-dral volume mesh generation, hybrid rnesh generation, and flow solver. Stere-olithography (STL) data are adopted as an interface between a CAD system and the surface grid generator. The surface triangulation method uses the advancing-front method coupled with geometric feature extraction technique to enhance the capability to treat complex geometries. This approach significantly reduces the work load to treat complex geometries. The flow solver for Euler/Navier-Stokes equations is parallelized by the domain-decomposition approach with MPI (Message Passing Interface) library. The mesh is partitioned by METIS with modification to create mesh overlapping between adjacent sub-domains for information exchange. Load balancing for the hybrid unstructured mesh comprised of tetrahedrons, prisms and pyramids is achieved by taking account of the number of edges in each sub-domain. The capability of the TAS code is demonstrated for flow simulations around an airplane and an insect.