Dynamic Modeling, Simulation, and Experimental Validation of the Power Take-Off Mechanism of an Oscillating Hydrofoil-Based Hydrokinetic Energy Converter

Abstract The study introduces the dynamic analysis of the Power Take-Off (PTO) mechanism of a Bio-Inspired Renewable Energy (BIRE) device aimed at revolutionizing riverine power generation. Inspired by the dynamics of fish swimming, an oscillating hydrofoil is utilized to harvest energy, which is converted via a Mechanical Motion Rectifier (MMR). This innovative PTO mechanism transmutes oscillatory motion into unidirectional rotation, ensuring high conversion efficiency. A ball screw-based MMR PTO was comprehensively examined using dry lab tests on an Instron machine and compared with a rack and pinion-based MMR PTO. The model prediction showed a commendable match with experimental data, with a primary focus on capturing frictional behaviors. Crucial findings indicated the prominence of dry friction, attributed to possible gear misalignments, which, when addressed, can significantly bolster the system’s mechanical efficiency. At an optimal load of 1 Ω, the PTO achieved an efficiency of 75%. Additionally, the distinct orientation of the force vs. displacement loop sheds light on inherent system dynamics, suggesting avenues for future refinements. This research lays the groundwork for a highly efficient and adaptable mechanism designed for harnessing riverine hydrokinetics.