A Parallel Navier-Stokes Method and Grid Adapter with Hybrid Prismatic/Tetrahedral Grids

A parallel finite-volume method for the NavierStokes equations with adaptive hybrid prismatic / tetrahedral grids is presented and evaluated in terms of parallel performance. The solver is a central type differencing scheme with Lax-Wendroff marching in time. The grid adapter combines directional with isotropic local refinement of the prisms and tetrahedra. The hybrid solver, as well as the grid adapter are implemented on the Intel Paragon MIMD architecture. Reduction in execution time with increasing number of processors is close to linear. A parallel communication strategy is presented and the resulting communication times remain about the same with an increasing number of processors. Subdivision of the grids into subdomains is based on the co-ordinates of the cell centroids and different partitionings of the hybrid meshes are considered. The execution times for parallel solution of viscous flow around the HSCT configuration with hybrid grids are presented for different grid partit..

Hybrid Grids for Viscous Flows around Complex 3-D Geometries including Multiple Bodies

A significant step towards routine viscous flow simulations around aircraft configurations using workstations is presented. The paper describes a method for the generation of hybrid prismatic /tetrahedral grids for complex 3-D geometries including multi-body domains and employs it for viscous flows around an aircraft. An Automatic Receding Method (ARM) is presented which treats narrow gaps in cases such as wing-engine configurations, as well as multi-element wings. The second development is a combined octree/advancing front method for the generation of the tetrahedra of the hybrid mesh. The method requires minimal user interaction to specify mesh parameters such as grid spacing and stretching. These parameters are determined automatically via an octree. The final quality of the tetrahedral mesh is improved using an automatic partial remeshing technique. Viscous flow solutions around the High Speed Civil Transport (HSCT) aircraft are presented. Both, subsonic and supersonic cases are co..