Numerical prediction of vortical flow over slender delta wings

Three-dimensional Navier-Stokes numerical simulations are necessary to correctly predict the complex leeward-side flow characteristics over delta wings, including leading-edge separation, secondary separation, and vortex breakdown. This article presents Navier-Stokes solutions of subsonic vortical flow over a 75-deg sweep delta wing with a sharp leading edge. The sensitivity of the solution to the numerical scheme is examined using both a partially upwind scheme and a central-differencing scheme. The effect of numerical grid density is also investigated. An embedded grid approach is implemented to enable higher resolution in selected isolated flow regions, such as the leeward-side surface flow region, and the leading-edge vortical flow region.