Flow-structure interaction (FSI) is important in high-speed flight because thin structures, such as the vehicle skin, are subjected to strong vibratory interaction with the flow. This interaction can lead to fatigue and failure of vehicle structures. We are investigating the flow-structure dynamic interaction of a compliant panel exposed to Mach 2 and Mach 5 shock-boundary layer interaction. The interaction is generated by a compression ramp that is located at the downstream edge of a flat compliant panel inserted flush with the floor of the wind tunnel. The flow-structure interaction is being studied by making simultaneous high-speed measurements of panel displacement, surface pressure and flow velocity using the digital image correlation (DIC), pressure sensitive paint (PSP) and particle image velocimetry (PIV) techniques, respectively.
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Lab personnel: Yoo-Jin Ahn, Marc Eitner, Mustafa Musta
Collaboratores: Prof. Jayant Sirohi
Sponsor: National Science Foundation
The FSI is currently being studied in the Mach 2 wind tunnel using brass and polycarbonate panels underneath a shock / boundary layer interaction generated by a 20 degree compression ramp. The configuration is show in the figure below. The compliant panels are 4.8 inches in length by 2.5 inches wide and have thicknesses that depend on the material. The brass panels have thicknesses of 0.01″, 0.012″, 0.016″, 0.020″ and 0.031″ giving first mode frequencies of 360 Hz, 410 Hz, 488 Hz, 600 Hz and 862 Hz, respectively.
Schematic showing the compliant panel under a Mach 2 compression ramp SBLI.