An Efficient Implicit Method for Solution of Compressible Turbulent Flows on Unstructured Grids

Reynolds-averaged compressible navier-stokes equations are solved using an implicit dual-time method on unstructured grids. the unstructured grid is generated using a novel successive refinement method where the surface and field grids are generated simultaneously. point and line sources are distributed in order to obtain the required grid length scales within the domain. the governing flow equations are discretised by an implicit approach in a real time basis while at each real time step marches the solution in a pseudo-time through an explicit time marching scheme. this approach allows the real time step to be chosen on the basis of accuracy rather than stability and it is not required to solve the large system of equations simultaneously. the k -b turbulence model equations are solved together with the main flow equations in a fully coupled manner. results are presented for several laminar and turbulent test cases and comparisons of the calculated pressure and skin friction coefficient distributions with the reference data showed good agreements. considerable computational savings are also achieved using the present implicit scheme over the fully explicit method.