Research on the test technique of Reynolds number variety in a hypersonic wind tunnel

Research on the test technique of Reynolds number variety is conducted in the Φ1m Hypersonic Wind Tunnel in CARDC to fulfill the needs of Reynolds numbers effect simulations for hypersonic vehicles. Because the run-mode of the Φ1m Hypersonic Wind Tunnel is high-pressure and vacuum-pumping, it owns a wide range of operational condition, the test Reynolds number can be changed by the way of stagnation pressure changing. The test technique of Reynolds number change consists of two types: single-point Reynolds number change method and continuous Reynolds number change method. The single-point Reynolds number change method keeps the stagnation pressures a fixed value to obtain aerodynamic coefficients with different attitude angles. The continuous Reynolds number change method keeps test model with a fixed attitude and continuously change stagnation pressure from high to low to obtain aerodynamic coefficients with different Reynolds number. The run-modes of wind tunnel, test measurement and data process method are presented in detail, and the validation tests of a lifting-body aircraft and a missile models have been presented. Combining continuous Reynolds number change method with single-point Reynolds number change method, we can completely and accurately obtain the aerodynamic characteristics of hypersonic vehicle with Reynolds number changing. The test results show the application prospect of this test technique.