On the improvement of the SIMPLE-like method for flows with complex geometry

For strongly nonorthogonal grids, the convergence difficulty is often encou ntered in the SIMPLE method unless very low relaxation factors are adopted. This is because that the cross derivatives of pressure corrections are usu ally neglected in deriving the pressure-correction equation. In this study, an approximate treatment is proposed to deal with the cross derivatives in the pressure-correction equation. Computations are performed for various l aminar flows in a nonorthogonal cavity and the turbulent flows through the compressor cascades. It is found that the convergence difficulty encountere d in the SIMPLE method for strongly nonorthogonal grids can be overcome whe n the SIMPLEC method is employed. In addition, when the present approximate treatment for the cross derivatives is adopted in the SIMPLEC method, the convergence rate can be speeded up in comparison with the original SIMPLEC method. In some cases, the CPU time can be decreased by more than 60%. The computational results are also compared with the numerical results of other s and the available experimental data.