Forced Boundary Layer Transition Experiments on a Multi-wedge in a Gun Tunnel

A series of wind tunnel experiments have been conducted to investigate the forced transition on hypersonic boundary layer transition on a multi-wedge in a gun tunnel. Two different trip configurations have been introduced on the first wedge, one is diamond shape and the other is swept ramp. The flow Mach number is 6 and the unit Reynolds number is 1.4 E + 07/m. The results show that when k/δ = 0.5, both of these two trips can cause transition and the diamond shape is much more effective than the swept ramp. When k/δ = 0.7, these two trips both can cause transition, but the diamond-shaped trip increases additional heating. Heat flux fluctuation results also show that when the trips are introduced, the flow goes directly to turbulence and rarely flow peaks can be found in the fluctuation signals.