Narrow Results

The lateral jet interaction on a slender body in supersonic flow was investigated by numerical simulation. The spatial and surface flow characteristics induced by jet interaction were shown. As a result, when the lateral jet is not in the longitudinal symmetry plane, the jet interaction causes asymmetric separation flow of surface and space, and destroys the pressure distributions of the slender body. With different angle of attack and circumferential positions of jet, the flow characteristic of the after body for jet in asymmetry plane changes greatly. The results with and without jet interaction also show that the far-field interaction played a major role in the lateral jet interaction.

Cai et al.⁵ developed a vortex stability theory for slender conical bodies and analyzed the stability of vortex pairs over slender conical wing-body combinations under small perturbations. An experimental study is presented in this paper to verify the validity of the theoretical predictions. A sharp-edged flat-plate delta wing is tested in a low-speed wind tunnel. A smoke-laser-sheet visualization technique is used to visualize and measure the positions of the vortex pair, which are found to be symmetric and conical over the wing. The same tests are performed on an identical delta wing model but with a flat-plate dorsal fin mounted vertically in the incidence plane of the wing. Two fin heights are tested. The ratios of the local fin height to the local wing semi-span are 0.75 and 1.50. The test results clearly indicate that the vortices become asymmetric and non-conical over the model with the fin height ratio of 0.75 and recover symmetry and conicity over the model with the fin height ratio of 1.50, providing direct experimental evidence of the theoretical predictions.

A pair of plasma actuators with horseshoe shape is proposed for dynamic manipulation of forebody aerodynamic load at high angles of attack. Preliminary wind tunnel pressure measurements show that asymmetric force over a conical forebody with semi-apex angle 10° can be manipulated by activating the plasma actuator mounted on one side of the cone tip. Further work is suggested.