Design and experimental study of a bypass dual throat nozzle with the ability of short/vertical takeoff and landing

Bypass dual throat nozzle (BDTN) is a new kind of fluidic thrust vectoring nozzle. A nozzle based on BDTN is designed, numerically simulated, and experimented to achieve short/vertical takeoff/landing (SVTOL). This novel nozzle, named BDTN-SVTOL, can realize the mode transition by rotating a specially-designed crescent-shaped component. The prominent advantage is that the aircraft can overcome the limitation of the runway length using bypass dual throat nozzle with a slightly different downwall. The main results show that the novel nozzle can obtain the ability of short/vertical takeoff/landing and supermaneuverability assisted by the fluidic thrust vectoring in only one set of nozzle. Therefore, the crescent-shaped component is the most important component of the novel nozzle. If the outer surface of the crescent-shaped component has no separation, the thrust direction changes by more than 80°. Results indicate that the separation occurs when the nozzle pressure ratio (NPR) is more than 1.5, leading to the decrease of the thrust vectoring angle (δ) and the lift efficiency (Cfy). Finally, the novel nozzle is not sensitive to size and Reynolds numbers of the inlet.