Study of fluid-structure interaction with undulating flow using channel driven cavity flow system

Fluid-structure interaction (FSI) induced by undulated flows was investigated using a channel driven cavity flow (CDCF) system. The bottom of the cavity section has a flexible plate made of either an aluminum alloy or carbon fiber composite, which interacts with flows in the cavity. Undulating flows were generated by controlling a series of solenoid valves programmed to interrupt the flow at various different frequencies from 0.5 to 1.25 Hz. Mean flow velocity was also varied for each given undulation frequency. The dynamic motion of the flexible test panel, made of aluminum alloy or carbon fiber composite, was measured for transverse deflections using laser displacement sensors. The study showed that the structural response was very dependent on the input flow. The plate vibrational modes had three to five dominant frequencies ranging from the undulated flow frequencies to about 5.0 Hz. Those frequencies were either at or very close to the multiples of the flow frequencies. The most dominant frequency was not always the same as the flow frequency, but it varied depending on the applied flow frequency.