A Three Dimensional Dual-Time-Stepping Method for the Solution of the Unsteady Navier-Stokes Equations

Abstract

A time-accurate flow solver for the two- and three-dimensional Reynolds-averaged Navier-Stokes equations has been developed. Up to now it is restricted to rigid body motions with three translational and rotational degrees of freedom. 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. Every processor of a computer or workstation cluster works on one or more blocks of the whole block structure. The communication.