Novel Instrumentation for the Measurement of the Unsteady Pressure Distribution around a Wing Undergoing Stall Flutter Oscillations

In this work, a wind tunnel model of a wing undergoing stall flutter oscillations is studied. It is a rectangular wing with pitch and plunge degrees of freedom and low pitch stiffness. The objective of this study is to promote the understanding of the stall flutter phenomenon by measuring the unsteady pressure distribution around the wing as well as the wing displacement, during unforced motion in two degrees of freedom. Both steady and unsteady pressures must be measured with sufficient accuracy during two types of tests. In the static tests the wing is to be clamped in position and not allowed to move and the steady pressures are to be measured around the centre-span section at different angles of attack. Thus the stall angle of attack can be identified and the stall mechanism characterized. In the dynamic tests the wing will be allowed to move and the unsteady pressures will be measured and recorded during a number of cycles of the oscillation, at a number of free stream airspeeds.