Hypersonic Flow Over an Elliptic Cone: Theory and Experiment

By applying hyper sonic approximations to Ferri's linearized characteristics method simple re suits were obtained for the shock shape and surface pressure distribution for an unyawed conical body of arbitrary cross-section. Calculations were carried out for an elliptic cone having a ratio of major to minor axis of 2:1, and a semi-vertex angle of about 12° in the meridian plane containing the major axis. An experimental investigation of the flow over this body conducted at a Ma.ch number of 5.8 in the GALCIT hyper sonic wind tunnel showed that the surface pressure distribution at zero angle of attack agreed quite closely with the theoretical prediction. On the other hand the simple Newtonian approximation predicts pressures that are too low. Surface pressure distributions and schlieren photographs of the shock shape were also obtained at angles of attack up to 14° at zero yaw, and at angles of yaw up to 10°, at zero pitch. At the higher angles of attack the Newtonian approximation for the surface pressures is quite accurate.