Developing a stress wave thrust balance for a hypersonic shock tunnel

The development of a thrust balance for the measurement of the net thrust produced in a scramjet nozzle is described. The balance has been designed and tested in the T4 shock tunnel at the University of Queensland. Numerical simulations of the balance and measurements made in the shock tunnel demonstrate that the thrust is correctly recovered when the loading in the nozzle is symmetric, but unexpected pressure asymmetry in some cases prevented successful recovery of the thrust.