Title: Numerical Simulations Based on Adaptive Delaunay Meshing Location: Building 980, Room 95 (Sandia-NM), Building 915, Room S101 (SNL-CA) Brief Abstract: Numerical simulations based on adaptive Delaunay meshing P. Frey, C. Dobrzynski and O. Pironneau CAD-based Navier-Stokes solvers are too expensive in some engineering fields; architecture and medical application to for blood flows are two such examples. In such fields, mesh generation and adaptation is also a bottleneck because the users are not expected to have the know-how. In this seminar we report on a Navier-Stokes solver for incompressible temperature and time dependent flows dedicated to architectural applications. The building blocks are not new: a finite element method with time implicit pressure projection steps and mesh adaptativity; but putting them together in an easy to use and efficient 3D code is the challenge which motivates this work. For non-engineering applications the user interface is a big problem. In an earlier attempt we designed Freefem3D based on a fictitious domain discretization, thus avoiding boundary fitted mesh. However it turned out that the display of the solutions requires a boundary fitted mesh; it is possible to generate a feasible surface mesh for graphics but it is much more difficult to generate a feasible surface mesh for FEM. In this project the user interface is taken from Freefem3d; then, with a marching cube algorithm we produce a graphic-only feasible mesh; finally a surface mesh, adapted to a FEM computation is constructed with an adaptation module and the result is used as input to a Delaunay volumic mesh generator (the solver is optimized and parallelized, all modules are the authors' work). CSRI POC: Philippe P. Pebay (925) 294-2024 |