Aerodynamic Force Measurement Techniques in JF12 Shock Tunnel

An aerodynamic force test was conducted in JF12 long-test-time shock tunnel. The test time of JF12 is 100–130 ms. The nominal Mach number is Ma7.0 and the exit diameter of the contoured nozzle is Ф2.5 m. The total enthalpy is 2.5 MJ/kg which duplicates the hypersonic flight conditions of Ma 7.0 at 35 km altitude. The test model is the standard aerodynamic force model of 10° half-angle sharp cone. The length of the test model is 1.5 m and the weight is 57 kg. The aerodynamic forces were measured with a six-component strain balance. The experimental results show that in the 100–130 ms test duration, the signals of strain balance have 3–4 complete vibration cycles. The aerodynamic force coefficients of JF12 are in good agreement with that of conventional hypersonic wind tunnels. This research demonstrates that aerodynamic force test can be conducted in shock tunnel with test time longer than 100 ms