Supersonic leeside flow topology on delta wings revisited

The leeside vortex structures on delta wings with sharp leading edges were studied for supersonic flow at the Institute of Theoretical and Applied Mechanics of the Russian Academy of Sciences in Novosibirsk. The experiments were carried out with three wings with sweep angles of chi = 68 degrees, 73 degrees, and 78 degrees and parabolic profiles in the 0.6 x 0.6 m(2) test section of the blow-down wind tunnel T-313 of the institute. The test conditions were varied from Mach numbers M = 2 to 4, unit Reynolds numbers from Re-1 = 26 x 10(6) to 56 x 10(6) m(-1), and angles of attack from x = 0 degrees to 22 degrees. The results of the investigations revealed that for certain flow conditions shocks are formed above, below, and between the primary vortices. The experimental data were accurate enough to detect the onset of secondary and tertiary separation as well as other boundaries. The various flow regimes discussed in the literature were extended in several cases. The major findings are reported.