Abstract: To simulate inflow conditions at flight Mach numbers of 5–8 under temporally controlled circumstances, a shock tunnel with a nozzle exit diameter of Φ150 mm was developed by integrating a controlled semi-free piston driven shock tube, a Laval nozzle, and a vacuum system. Using helium as the driver gas and air as the driven gas, the following four-stage process was implemented: Compression control, Initiated diaphragm rupture, Stagnation heating, and Nozzle acceleration. At the tailored condition, the system achieved a maximum total temperature of 2,700 K and total pressure of 6.0 MPa. Under beyond-tailored conditions, it simulated inflow equivalent to flight Mach 8.0. Preliminary results demonstrate that combining the controlled semi-free piston driven shock tube with a high-flow high-pressure gas control system and precision diaphragms effectively regulates rupture timing. The repeatability of sequential control across multiple tests reached an accuracy of ±0.2 ms.

Keywords: shock tunnel; diaphragm rupture; Mach number; temporally controlled