A controllable pulsed jet wind shear generator for hypersonic wind tunnel experiments

In recent years, the rapid advancement of hypersonic vehicles has led to increasing attention on the impact of high altitude wind fields on these vehicles. A novel wind shear generator designed to investigate the effects of incoming wind shear on both internal and external flows during hypersonic wind tunnel experiment is introduced. The device generates oblique shock waves upstream of the model to alter the angle of the incoming flow. By utilizing a motor-driven rotating plug and adjusting the opening of the ball valve, the system can produce a dynamic flow characterized by a specific disturbance amplitude and frequency, without modifications to the existing wind tunnel equipment. In this study, the operational effectiveness of the device was evaluated under conditions where the incoming flow Mach number was 6. Utilizing pressure measurement and schlieren techniques, we analyzed the leading-edge shock angle, Mach number within the boundary layer. The results demonstrate that the device can generate dynamic incoming flow with consistent disturbance amplitude, frequency, and period at Mach 6. This experimental setup effectively addresses the challenge of producing wind shear using a simple apparatus in wind tunnel experiment, providing a foundation for studying the influence of wind shear on the internal and external flows of aircraft.