Effects of sweep angle and passive relaminarization devices on a supersonic swept-cylinder boundary layer

The effects of passive leading-edge devices on the boundary layer of a swept cylinder in supersonic flow with very low free-stream disturbance levels are investigated. Tests are conducted at Mach 3.5 over a free-stream Reynolds number based on model diameter of 15,000 to 150,000, and sweep angles of 60 deg and 76 deg are used to evaluate possible sweep-angle effects. The devices tested include a sawtoothed leading edge, square device, and a fence. It is observed that at a sweep angle of 76 deg, relaminarization of the supersonic attachment-line flow is achieved by several of the devices, while no devices are successful at a sweep angle of 60 deg.