Supersonic Retropropulsion Experimental Results from NASA Ames 9×7 Foot Supersonic Wind Tunnel

Supersonic retropropulsion was experimentally examined in the Ames Research Center 9 x 7 Foot Supersonic Wind Tunnel at Mach 1.8 and 2.4. The model, previously designed for and tested in the Langley Research Center Unitary Plan Wind Tunnel at Mach 2.4, 3.5, and 4.6, was a 5-in.-diam 70 deg sphere-cone forebody with a 9.55-in.-long cylindrical aftbody. The forebody was designed to accommodate up to four 4:1 area ratio nozzles, one on the model centerline and the other three on the half-radius spaced 120 deg apart. Surface pressure and flow visualization were the primary measurements, including high-speed data to investigate the dynamics of the interactions between the bow and nozzle shocks. Three blowing configurations were tested with thrust coefficients up to 10 and angles of attack up to 20 deg. Results and observations from the test are provided.