Experimental and computational results of a cone-slice-ramp geometry at mach 6

Experiments were performed in the Boeing/AFOSR Mach-6 Quiet Tunnel on a cone-slice-ramp geometry. The cone half-angle was 9^◦ . Ramp angles of 5^◦, 10^◦, 20^◦, and 30^◦ from the centerline of the model were tested at a unit Reynolds number of 11.3×10⁶ /m. Computations were performed at similar conditions using the NASA OVERFLOW solver. With the 5^◦ and 10^◦ ramps under quiet flow conditions, experiments measure three streamwise streaks of heating on the slice. These streaks do not occur with the 20^◦ and 30^◦ ramps. Surface pressure sensors measure disturbances for several conditions on the slice and ramp, but it currently cannot be determined experimentally if the flow is laminar or dominated by large separated regions. Under noisy flow, two large turbulent wedges develop on the slice region for all four ramp angles. The turbulent boundary layer remains attached when the flow encounters the ramp. Three streaks are also computed for ramp deflection angles of 10^◦, 20^◦, and 30^◦ . The 5^◦ case has not been computed. The cause of the discrepancy in the number of streaks on the slice for the 20^◦ and 30^◦ cases is being investigated. On the deflected ramp surface, similar heating rates and patterns occur in the computations and experiments.