High accuracy wake and vortex simulations using a hybrid Euler/discrete Vortex method

A new approach has been developed which preserves vortices over long distances. This new hybrid Computational Fluid Dynamics/Discrete Vortex (CFD/DV) method couples a Lifting-Line/Free-Wake method with an unstructured grid, parallel 3-D finite volume CFD flow solver. The total solution field is separated into two, the potential flow solution of the DV method and the rest of the flow field. The modified Euler equations are then solved and the total solution field is obtained. The tip vortex and wake of a fixed rectangular wing is investigated as a starting point. The solutions obtained with the hybrid metiiod are compared to those without the hybrid method. The results show that the tip vortex shed from the wing tip is preserved over long distances when the hybrid CFD/DV method is applied. The wing tip vortex is quickly dissipated due to numerical diffusion in solutions with no hybrid method implementation.