Development of parallel incompressible NS solver on stretched grids
Abstract
Development of a parallel NS solver for studying DNS and LES of temporal mixing layers is discussed. The equations are cast in strong conservation form on a uniform computational mesh, transformed from a stretched mesh in the physical domain. Variables are defined on a collocated grid, and the transformed equations are solved using a fractional step method. Convective and dissipative terms are treated using explicit AdamsBashforth and implicit CrankNicolson, respectively. Fourth order spatial accuracy is maintained except for hyperviscous subgrid model terms, which are only 2nd order accurate. The block LU analysis of J. B. Perot, extended to fractional step methods on collocated grids, shows that an O(Δ t^2) term involving the pressure gradient must be added to the momentum equations to maintain 2nd order accuracy in time. Using a smaller stencil for the pressure gradients largely simplifies the pressure Poisson equation while still ensuring that discrete continuity is satisfied to appropriate order. Implementation on distributedmemory multiprocessors is achieved using MPI, with care taken to minimize communication overhead.
 Publication:

APS Division of Fluid Dynamics Meeting Abstracts
 Pub Date:
 November 2003
 Bibcode:
 2003APS..DFD.MH009J