Design of Micro Hydrokinetic Energy Harvester of Marine Animal Movement for Underwater Monitoring

Abstract

The underwater mobile monitoring platform that utilizes marine animals as carriers provides a new solution to address the issues of short endurance, high costs, and bulky size associated with traditional underwater mobile monitoring platforms. Based on most marine animals that have the behavioral habit of long‐duration swimming, a micro hydrokinetic energy harvesting system is proposed. This system applies a miniature vertical‐axis water turbine as its energy conversion component. The hydrokinetic energy is derived from the relative movement between marine animals and the surrounding seawater. A conceptual design of a novel underwater mobile monitoring platform is presented. A finite element model of the external‐rotor permanent magnet synchronous generator is established to comprehensively evaluate the performance of the generator. Numerical simulation is utilized to conduct a comparative analysis of different diversion channel designs. Preliminary water tank experiments show that the designed micro energy harvester can effectively capture the hydrokinetic energy generated by water flow movement. The startup flow rate of the harvester is around 0.16 m s−1. The output power increases with the increase in water flow velocity, reaching a maximum value of ≈57 mW within the range of water flow rate of about 0.2–0.5 m s−1.