Effect of Thrust-Vectoring Jets on Delta Wing Aerodynamics

The interaction of thrust-vectoring jets with leading-edge vortices over stationary delta wings and its effects on the wing aerodynamics were investigated experimentally. Two models with sweep angles of A = 50 and 65 deg, representing nonslender and slender wings, respectively, were tested with rectangular and circular nozzles. Force, velocity measurements, and flow visualization were performed. It was found that undervortex blowing can significantly affect the aerodynamic forces on both nonslender and slender wings. The maximum lift change occurred near the stall angle, due to the earier reattachment of shear layer and delay of vortex breakdown. Force measurements revealed that the effect of nozzle geometry can be important, because the entrainment effect of the jet depends on it. The jet-vortex interact on, distortion of jet vortices, and merging of wing and jet vortices are more pronounced for the rectangular nozzle and have a larger influence on the delta wing aerodynamics. The effect of the jet yaw angle is small for the nonslender wing, whereas the aerodynamics of the slender wing is very sensitive to the jet yaw angle.