Computational and experimental study of trailing vortices

A coordinated computational undertaken to investigate the and experimental study was behavior of the vortices trailing from low aspect ratio lifting surfaces. Vortex formation in the near-wake was measured in a wind tunnel with yaw-head and hot-wire probes at three different Reynolds numbers, the highest of which was greater than most previous studies. These near-wake measurements provided initial conditions for the far-field computation with the parabolized Navier-Stokes equations written in terms of vorticity and stream function. Turbulent transport was modeled through the turbulent kinetic energy and the Prandtl-Kolmogorov hypothesis to give an eddy viscosity. The experimental results showed that the effects of Reynolds number are significant for vortex formation in the nearwake, and the computation adequately effects. However, the decay trend in the far-field is essentially unaffected by the Reynolds number, and the predicted decay for maximum tangential velocity agreed very well with Iversen's correlation.