Small Piezoelectric Waterjet Propulsion System Design

Propeller is the core component of marine power conversion which put the energy generated by the engine into the forward momentum of the ship. Water-jet propeller which uses high speed jet flow to push the ship forward has many advantages, such as excellent anti-cavitation performance and flexible operation, which make it universal application in the high-speed ship. But traditional water-jet propeller also has many shortcomings, such as complicated mechanical structure, large volume, heavy weight, big noise, complex replacement and maintenance for the propulsion pump and so on, which make it difficult to miniaturize of underwater unmanned aircraft. So the researches have try to develop a water-jet propulsion device with small volume, high control precision, low noise characteristics. In this dissertation, a kind of small piezoelectric water-jet using the inverse piezoelectric effect is designed and studied. The piezoelectric water-jet propulsion has many advantages. Which uses simple structure, small size, no electromagnetic interference, and no noise, It has potential applications in micro and small unmanned underwater detectors, miniature underwater robots, toy boats, submarines and other underwater vehicles.The main work and innovations are as follows:1. The principle and the basic mechanical structure of piezoelectric water-jet propeller are given. The outline of the piezoelectric water-jet propeller is proposed and the sound pressure distribution of the piezoelectric transducer in water is simulated by COMSOL software. Simulation study shows that the sound field of the piezoelectric transducer can generate a certain force in water.2. According to the requirements of the system design, the drive circuits of the propeller are designed in this dissertation. The parameters of the DC-DC boost circuit, SCM control circuit and oscillation circuit are given and the circuits are made experimentally.3. The performance of the circuits for piezoelectric water-jet propulsion system are tested. And the prototype of the piezoelectric water-jet propeller is tested to verify the feasibility of the piezoelectric water-jet propulsion system.The research results in the dissertation have certain significance to the application of the piezoelectric water-jet propulsion system in underwater power drive.