Aeroelastic Stability of Flat Rectangular Shell Structures in High Subsonic and Low Supersonic Flow

Abstract

Shells exposed to supersonic flow can become aeroelastically unstable under certain flow conditions caused by negative aerodynamic damping. The resulting aerodynamic loads depend on the flow's Mach number and its Reynolds number. Experiments were performed in the Transonic Wind Tunnel Göttingen on rectangular and flat plates. Using a forced excitation approach, the structural parameters amplitude and excitation frequency were varied for two simulated eigenmode shapes. High-resolution pressure and deformation measurements allowed the determination of the local pressure responses and the global Generalized Aerodynamic Forces. The influences of the parameters on the resulting pressure response could be determined under subsonic and supersonic flow conditions. Characteristic changes in the transition to supersonic flow were found. All domains measured in supersonic flow showed a positive aerodynamic damping of the aeroelastic system.