Force Measurements in Aeroelasticity Using Piezoelectric Multicomponent Transducers.

Abstract

Contrary to conventional strain gauge balances, a piezo balance features high rigidity and low interferences. High rigidity leads to very high natural frequencies of the balance itself, which is a prerequisite for applications in aerodynamics and particularly in aeroelasticity. Concerning the measurement of small steady forces, the application of piezo balances is restricted due to a drift of the zero point. However, this problem is not as critical as generally believed and will be discussed. The paper is focused on results from steady and unsteady measurements with a wing/engine combination in a low speed wind tunnel and on flutter tests with a swept-wing performed in the Transonic Wind Tunnel in Modane. In orderto demonstrate the very large measuring range drag coefficients of bluff bodies measured in a pressurized wind tunnel are presented. Based on these examples, the fundamental aspects will be discussed, which are essential in designing and applying piezo balances.