Supersonic flow generation and sustenance in an optimized wind tunnel in conditions of Martian atmosphere

Mars’s low-pressure, low-Reynolds-number environment makes aerodynamic stability and control extremely challenging during supersonic entry, descent, and related processes. We proposed a Martian supersonic wind tunnel where quasi-isentropic expansion in the nozzle generates supersonic flow and multi-point ejector suction maintains it in the test section. To accelerate the flow to the desired supersonic state, the nozzle featured a combined arc and straight-line front contour and an analytically determined rear contour. The multi-point ejector system was optimized to maximize suction, with 0.04, 9, and 13 × 13 identified as the optimal area ratio, throat-to-exit area ratio, and ejector array, respectively. The proposed wind tunnel can accommodate large-scale testing with dimensions of 1.6 m × 1.6 m × 3.5 m under simulated Martian conditions. Computational Fluid Dynamics (CFD) results indicate that a stable flow field with velocities exceeding 520 m/s can be established over '90% of the cross-sectional area within the supersonic operating region. This wind tunnel can be used for ground testing of Martian supersonic systems, including parachutes, rotorcraft, and other aerodynamic configurations, thereby providing critical experimental support for the development of future Mars exploration vehicles and deep-space missions.