ADAPTIVE PRISMATIC-TETRAHEDRAL GRID REFINEMENT AND REDISTRIBUTION FORVISCOUS FLOWS

A hybrid grid adaptive algorithm that combines grid refinement and red istribution suitable for three-dimensional viscous flow simulations is presented. The flow domain is discretized with both prismatic and tet rahedral elements. The prismatic region comprises successive layers of semistructured prisms that encompass regions close to the wall where the viscous effects are dominant. The grid outside the prismatic regio n is tessellated with tetrahedra. A hybrid grid adaptation scheme that implements local refinement and redistribution strategies is develope d to provide optimum meshes for viscous flow computations. Grid refine ment on a hybrid grid is a dual adaptation scheme that couples isotrop ic division of tetrahedra and directional division of prisms. The dire ctional division of prisms is essentially a two-dimensional grid refin ement scheme that results in a significant reduction in required compu ting resources. The grid adaptive solver yields accurate results as co mpared with a globally refined grid with reduced computing resources.