A Buckled Plate as a Hydrokinetic Energy Converter

We experimentally study the influence of a structural buckling instability as a novel concept to extract hydrokinetic energy. First, we show proof of concept of two coupled thin elastic plates buckled into a second mode-like deformation created by applied external net compressive force. We subject the deformed device to an incompressible flow to induce oscillations, and very much like a peristaltic pump, we show how the proposed device is capable of pumping water above the energy grade line in which it is immersed. Second, we elucidate the physical mechanics behind the proposed fluid structure interaction. Based on image-based edge detection, acoustic Doppler velocimetry, and particle image velocimetry, we determined that the destabilizing action of the compressive force, deformed locally-stable plates, and a non-zero pressure drag, all existent prior to structural oscillations, are the main contributors towards energy extraction in such device. The underlying objective is to create a device that is capable to operate in a broader range of flow conditions, especially low flow velocities.