Response of a Flat Plate to Fluid-Structure Interaction in Hypersonic Flow

Modern-day requirements for long-duration air-breathing propulsion-based manoeuvrable hypersonic vehicles lead to thin, lightweight structures prone to fluid-structure interactions. The high degree of nonlinearity and strong Multiphysics coupling makes hypersonic aeroelastic predictions challenging. Aeroelastic instabilities have mission-critical consequences. Therefore, a fundamental understanding leading to accurate modelling and prediction is important for the development of robust hypersonic flight vehicles. This work presents the study of fluid-structure interactions on a cantilevered flat plate at Mach 6.5 flow. Experiments were performed to investigate the aeroelastic response of the panel and flowfield because of the coupling. The flat plate was tested at different angles (10 deg. and 20 deg.), and the plate's thickness was varied (2 mm and 4mm). During the experiments, the acceleration of the plate was measured using accelerometers, and the flow field was observed using high-speed Schlieren photography. Spectral analysis of accelerometer data shows that structural response is dominated by natural frequency modes. These peaks are associated with their corresponding structural modes using Dynamic mode decomposition (DMD). For a thinner plate, the dominant frequency increases with an increasing angle of attack. This work characterises the effect of the angle of attack on the structure response.