An accelerometer balance for the measurement of roll, lift and drag on a lifting model in a shock tunnel

Abstract

A force balance to measure roll, lift and drag on a lifting aerodynamic body in an ultrashort-duration hypersonic test facility, such as a shock tunnel, has been developed and tested on a flapped, blunt-nosed, triangular lifting body at a freestream Mach number of 8. The flow total enthalpy and the freestream unit Reynolds number were 0.83 MJ kg−1 and 0.98 million, respectively. The balance structure has a soft suspension that allows the model to have a free flight during the short-duration aerodynamic test. The balance was mounted inside the hollow model and was equipped with accelerometers to sense the aerodynamic moment and forces on the model. The measurements were carried out at different angles of incidence of the model and the acquired signals of the accelerometers were reduced to the aerodynamic moment and the force coefficients based on the theories of applied mechanics and aerodynamics. Also, the moment and force coefficients were theoretically calculated based on the Newtonian theory, which is an accepted analytical approach for hypersonic bodies. Good agreement has been observed between the experimental and the analytical results. The method of measurement of roll and lift, and the data on the rolling moment of a lifting body presented in this note are novel.