Numerical Investigation of a Simplified Wing–body Junction Flow

The flow past a simplified wing-body junction configuration is simulated using a shear layer adaptive improved delayed detached-eddy-simulation (SLA-IDDES) approach in which an appropriate subgrid lengthscale is adopted in the boundary region, where the grid may be strongly anisotropic, to prevent the excessive generation of subgrid-scale eddy viscosity. The numerical results show overall good agreement with the experiment carried out by Ölçmen and Simpson. The self-induced chaotic switching of the horseshoe vortex between two flow modes is simulated and analysed, and its effects on the vortex legs and their inherent oscillation are also investigated. It is found that the corner vortex also exhibits an alternating formation and breakdown process with basically the same frequency as the horseshoe vortex. Corner separation is found to be affected also by the upstream horseshoe vortex and the inherent oscillation of the vortex legs.