Development and application of the force-measuring balance in impulse combustion wind tunnel tests

A design scheme of strutting internal six-component strain gage balance is developed to meet the requirements of aerodynamic load tests for big-weight hypersonic models under cold and hot conditions in the impulse combustion wind tunnel. The fast-response ability of balances is crucial in hypersonic force-measuring tests because of short test duration, serious impulsive load and big model weight. The mutually exclusive stiffness and sensitivity are coordinated. The balance is qualified according to static calibration results. Demonstrated by the test results, the consistency between the output signal of the balance and the combustor pressure is good, which indicates that the balance accurately reflects the aerodynamic loads of the model. Stability of the balance is confirmed by the axial force coefficient precision of 1.6% in the repeated calibration tests, and the eigen frequencies of the axial force, normal force and pitch moment signal satisfy the criteria in impulse wind tunnel tests. In conclusion, the balance has met the requirements of aerodynamic load tests of hypersonic vehicle models in impulse combustion wind tunnels.