IMPROVED EULER SIMULATION OF HOVERING ROTOR TIP VORTICES WITH VALIDATION

An improved spatially third-order accurate rotor Euler/Navier-Stokes solver and a grid redistribution method have been developed to reduce the numerical diffusion of vorticity contained in rotor Euler/Navier-Stokes analysis. It has been shown that the application of both methodologies to simulate hovering rotor flowfield can result in a significant reduction of numerical diffusion of the tip vortex structure. The comparison of the predicted tip vortex core growth with the experimental data has indicated that with the improvement of both flow and grid solvers, the numerical diffusion of the direct Euler simulation based on a grid with only about half a million grid points, is at the same level as the viscous diffusion before the first blade passage.