Investigation of the engine-gear vortex with LIDAR and CFD

The final approach and touchdown of a landing aircraft is studied numerically with a hybrid RANS/LES approach, as well as a pulsed coherent LIDAR system. Particular emphasis is put on the ground effect, the engine-gear vortex and the wake vortex evolution before and after touchdown. We compare CFD results with LIDAR measurement data collected in a recent campaign at Vienna airport. The radial velocity method was applied to retrieve vortex position and circulation. The vortex structures predicted by the simulations are clearly visible in those measurements. Simulated tangential velocity profiles are compared with vortex model profiles. It is observed that the standard vortex model can be improved including mirror vortices.