Effects of Mach Number on Supersonic Wraparound Fin Aerodynamics

摘要

An experimental Mach number parametric (M ∈ [2-15, 3.83]) study was conducted to investigate the apparent rolling-moment reduction with increasing Mach number noted in flight-test experiments. The aerodynamic loading and the surface flow in the fin region of wraparound fin missiles in high-Reynolds-number (Re_C ∈ 0.3 x 10~6 to 0.9 x 10~6) supersonic cross streams were investigated using photoluminescent pressure-sensitive paint and surface oil-flow visualizations with fluorescent pigment as the seeding medium. Schlieren photography was used to characterize the fin-generated shock structures. Two curved-fin missiles were tested, one having a solid fin and the other a slotted fin. The fin pressures were integrated for rolling moments; these data confirm the solid-fin missile reduction in rolling moment with increasing Mach number. The slotted-fin missile exhibited a similar rolling-moment Mach number dependence. Analysis of the pressure distributions, surface streamlines, and shock structures indicated that the flowfields experienced very strong and complicated inviscid—viscous interactions and that these interactions had a significant impact on the aerodynamic loading of the fins. Finally, the slotted-fin missile demonstrated the potential for increased roll stability and reduced wave drag.