Experimental and Analytical Investigation of Hypersonic Fluid-Structure-Interactions on a Pitching Flat Plate Airfoil

Abstract

Understanding the effects of unsteady flows is a critical area of hypersonic research. This paper presents a comparison of experimental results and analytical tools commonly used for the prediction of fluid structure interactions: Piston theory, Van Dyke’s theory, and Unsteady Shock Expansion theory. The investigation is carried out with a wedge-nosed flat-plate airfoil with pitching degree-of-freedom at Mach 6 flow conditions.High-speed Schlieren video is used to extract data about airfoil pitching motion and the unsteady shock structure. These data are compared to predictions from the various methods giving insight into their capability to correctly predict surface pressure and the resulting pitching motion at a reduced frequency, k=6.3×10-3. Contrary to expectations for this quasi-steady flow regime, the analysis of the shock structure shows hysteresis, indicating additional viscous interactions.