| Popis: |
A time-accurate flow solver for the three-dimensional Reynolds-averaged Navier-Stokes equations has been developed. An implicit time discretization is used, and the resulting set of coupled non-linear equations is solved iteratively. This is accomplished using well proven convergence acceleration techniques for explicit schemes such as multigrid, residual averaging, and local time stepping, in order to achieve large computational efficiency in the calculation. The approach, known as dual-time stepping in literature, allows the physical time step to be chosen on the basis of accuracy rather than stability. The method is parallelized using the domain decomposition technique. Results are presented for three-dimensional transonic flows around the oscillating LANN-wing. The large speed-up made possible through dual-time stepping and parallelization is pointed out. Using the Baldwin-Lomax turbulence model, good agreement of the pressure coefficient with experimental data is shown for attached flows. The shock induced separation for the LANN-CT9 test case is predicted too far downstream. |
