Abstract:
A new aerodynamic model was developed for the flow field simulation of a rotor in transient flight with ground effect. In the new model, a stable and efficient time-stepping free-wake algorithm CB3D is used to determine the wake geometry, and the ground is modeled with a panel method. In consideration of unphysical phenomenon that a part of the wake vortices may be generated under the ground in the numerical prediction, a constant volume rectifying method is incorporated to rectify the position of the unphysical wake vortices. The analysis results of the new model show that, for a rotor at various advance ratios with ground effect, the predicted recirculation and ground vortex flow regimes agree well with the experimental images with respect to the location and vorticity, which could provide an insight for the rotor transient flying in ground effect.