Publications Details
Fluid-structure interactions on a slender cone under quiet flow conditions at Mach 6
Fluid-structure interactions were studied on a 7° half-angle cone in the Purdue Boeing/AFOSR Mach 6 Quiet Tunnel. A thin carbon-composite panel was integrated into the cone and its response to boundary-layer disturbances was measured. Under quiet flow, the cone boundary layer remained laminar. A spark perturber was used to create turbulent spots in the boundary layer at frequencies between 0.1 and 10.5 kHz. Isolated turbulent spots excited a directionally dependent panel response which would last much longer than the spot duration. At higher repetition rates, the panel response did not damp out before the subsequent spot. When the excitation frequency matched a structural natural frequency of the panel, resonance would occur in the directions associated with the mode shape. It was harder to excite spanwise vibration at lower frequencies because of the dominant axial and wall-normal forcing created by the controlled turbulent spots. At higher frequencies, spanwise resonance could be more easily excited, likely because the highly coupled mode shapes associated with those frequencies provided a path for energy transfer.