Investigation of wind tunnel balance dynamic characteristics' multi-order inertial compensation

The structural vibration of the aerodynamic measurement system can be actuated by impulse loads or dynamic loads in aerodynamic measurement tests of hypersonic wind tunnels. Therefore, the useful data and the vibration noise are mingled. The accuracy of the present balance dynamic compensation method is poor since the processing method is over simplified. We simplify the force measurement system to a cantilever beam with an end mass determined by its structural characteristics, and obtain its analytical solutions for free vibration. Study of the free vibration is focused on the impacts of different vibration shapes on force measurement, and the distribution disciplines of acceleration of different vibration shapes. We put forward a new compensation method named 'multi-order inertial compensation method', and obtain the corresponding theoretical compensation coefficients. What's more, we validate this method by finite element analysis and wavelet analysis. The results show that the multi-order inertial compensation method significantly improves the dynamic characteristics of the balance compared with conventional method.