Accession Number:

ADA237203

Title:

Implicit Solvers for Unstructured Meshes

Descriptive Note:

Contract rept.,

Corporate Author:

INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Report Date:

1991-05-01

Pagination or Media Count:

24.0

Abstract:

We develop and test implicit methods for unstructured mesh computations. The approximate system which arises from the Newton linearization of the nonlinear operator is solved by using the preconditioned GMRES generalized Minimum Residual technique. We investigate three different preconditioners, namely, the incomplete LU factorization ILU, block diagonal factorization and the symmetric successive over-relaxation SSOR. The preconditioners have been optimized to have good vectorization properties. We also study SSOR and ILU themselves as iterative schemes. The various methods are compared over a wide range of problems. Ordering of the unknowns, which affects the convergence of these sparse matrix iterative methods, is also investigated. Results are presented for inviscid and turbulent viscous calculations on single and multi-element airfoil configurations using globally and adaptively generated meshes.

Subject Categories:

  • Aircraft
  • Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE