Combined Free Wake / CFD Methodology for Predicting Transonic Rotor Flow in Hover

A new combined wake / CFD methodology is used to include realistic wake effects in CFD solutions for the rotor flow in hover. The analytical method for predicting the hovering rotor wake is described to investigate the motion of the helical tip vortex. Beginning with the generalized wake model, a Semi-Empirical Correction for the vortex core effect on the rotor wake is made. Then on the condition of circulation and wake geometry convergence, the free wake calculation is carried out. Finally, Euler equations are solved for transonic rotor flow employing Jamesonʹs finite-volume explicit Runge-Kutta time-stepping scheme. The results are compared with the respective references and experimental data.