Experimental Investigation of the Flow Structure Near a Single Wraparound Fin

The flow structure near a single wraparound fin on a wall-mounted semicylindrical model was experimentally investigated at Mach 2.8 (Re/l = 18 106 m-1). Detailed mean flow and turbulence measurements were obtained using conventional pressure probes and cross-wire hot-film anemometry at a series of stations near the fin. Large flowfield asymmetries were observed in both mean flow and turbulence measurements aft of the shock/boundary-layer interaction. Measured turbulence intensities in the fuselage boundary layer were far greater on the concave side of the fin than on the convex side. On the convex side of the fin, the turbulence intensity levels were 30% lower than the preinteraction values, and on the concave side a 50% increase was observed. Similarly, the Reynolds shear stress levels aft of the fin bow shock decreased on the convex side of the fin while increasing dramatically on the concave side. These results are consistent with the stabilizing and destabilizing effects of pressure gradient distortion on supersonic boundary layers.

Experimental Investigation of the Flow Structure Near a Single Wraparound Fin Academic Article