Fluid-Structure Interaction of a Planar Shock Impinging on a One Degree-of-Freedom Axisymmetric Body in Mach 5 Flow*

The fluid-structure interaction resulting from an oblique shock impinging on a structurally-compliant slender axisymmetric model is experimentally investigated in a Mach 5 blowdown wind tunnel. The model is comprised of a 5-degree half-angle rigid cone attached to a rigid cylinder by using an elastic flexure element to provide one degree-of-freedom in the motion of the cone. The planar shock-wave is generated from a compression ramp upstream which induces a low-frequency unsteadiness from the turbulent shock-wave/boundary-layer interaction (SWBLI). This low-frequency oscillating shock interacts with the conical shock before impinging on the cone in what is known as a Type-I shock impingement. The low-frequency unsteadiness from the shock couples with the natural frequency of the elastic slender vehicle which is restricted to motion in one degree-of-freedom. Fast-response pressure-sensitive paint (PSP) will temporally resolve the pressure forcing on the cone while direct imaging enables tracking of its motion. In addition to the high-speed PSP, important flow characteristics on the surface will be compared between the compliant and the rigid model through surface oil flow. High frequency particle image velocimetry (PIV) will measure the velocity components of the shock impingement and its effects downstream caused by the interaction with the structural motion.