Simulation of Streamwise Vortices at the Flaps of Re-entry Vehicles

Kurzfassung

Purpose of the present investigation is the numerical investigation of separated flow in the flap region of the X-38 re-entry demonstrator, with respect to the heat loads downstream reattachment induced by streamwise vortices. As a first step generic turbulent ramp configurations with artificially induced vortex disturbances have been simulated by the Navier-Stokes solver CEVCATS-N and compared with wind tunnel data of the Ludwieg tube facility in Göttingen (RWG). The results allow a deeper insight into the perturbed flow field, the associated flow topology and the influence of different parameter variations for the perturbations. For the resolution of streamwise vortices in the boundary layer of the control surfaces of re-entry vehicles local grids have been generated at the flaps of the X-38. Extensive studies of the grid influence on the wake and on further distant flow as well as grid refinement in different directions have shown a very good grid convergence. Streamwise vortices are simulated on spanwise refined grids with a highly resolved boundary layer. For laminar cases and cases with fixed transition vortex influences are simulated successfully with and without artificial vortex excitation.