Further Development of a Viscous Vortex/Wing Interaction Program.

A computational fluid mechanical model developed for analyzing the loads and flow mechanism due to vortex/wing interactions has been further improved and evaluated. The model provides vorticity, velocity vectors, and pressures for viscous flow on the upper surface of the wing with a leading edge vortex. Viscous parametric investigations have been conducted showing the effects of such parameters as leading edge sweep, leading edge feeding vorticity, and viscosity. Effects of grid size and various boundary conditions are presented. Boundary conditions are determined from potential flow models by an iteration procedure. Directions and an example of the interaction procedure is presented. A simple 65 deg delta wing at 22 deg angle of attack is used for the analyses. Iterations for this model are not complete, but the results are instructive for analyzing other models and completing the 65 deg wing investigation. The method is not limited to thin delta wings. Arbitrary planforms can be evaluated. Thick wings with rounded leading edges are under current investigation. Experimental laser velocimeter data are presented for boundary conditions at one station on the 65 deg delta wing at 22 deg angle of attack. (Author)