Wk. Anderson et al., IMPLICIT MULTIGRID ALGORITHMS FOR INCOMPRESSIBLE TURBULENT FLOWS ON UNSTRUCTURED GRIDS/, Journal of computational physics, 128(2), 1996, pp. 391-408
An implicit code for computing inviscid and viscous incompressible flo
ws on unstructured grids is described. The foundation of the code is a
backward Euler time discretization for which the linear system is app
roximately solved at each time step with either a point implicit metho
d or a preconditioned generalized minimal residual (GMRES) technique.
For the GMRES calculations, several techniques are investigated for fo
rming the matrix-vector product. Convergence acceleration is achieved
through a multigrid scheme that uses nonnested coarse grids that are g
enerated using a technique described in the present paper. Convergence
characteristics are investigated and results are compared with an exa
ct solution for the inviscid flow over a four-element airfoil. Viscous
results, which are compared with experimental data, include the turbu
lent flow over a NACA 4412 airfoil, a three-element airfoil for which
Mach number effects are investigated, and three-dimensional flow over
a wing with a partial-span flap. (C) 1996 Academic Press, Inc.