Session: 09-03-02 Tidal Energy: Hydrodynamics

Paper Number: 125795

125795 - Hydrodynamic Performance of a Pitching Circular Motion Hydrofoil for Tidal Current Energy Harvest 

 Considering that if a pitching hydrofoil moves in a circle, the mechanical structure of the turbine can be further simplified, which is much simpler than a traditional oscillating hydrofoil tidal current turbine, therefore the performance of a pitching hydrofoil with such simple trajectory has attracted our interest. In this paper, numerical method was adopted to simulate a pitching circular motion hydrofoil with variety of motion parameters. Before that, the method was verified and validated. Then, instantaneous hydrodynamic forces, vortex flow field, pressure distribution and power coefficients of the hydrofoil were studied. More importantly, the effect of pitch amplitude and circular motion frequency was investigated. Results show that, the vertical force (lift) is the main power for the hydrofoil to harvest energy. For most of the time in a period, the horizontal force and pitch moment do negative work. The favorable interaction between vortex and hydrofoil can increase the positive work done by the lift and reduce the negative work done by horizontal force and pitch moment, thus improving the energy harvest efficiency. There are optimal values for the two main motion parameters, which can maximize the energy harvest efficiency. When the pitch amplitude is 75 degrees and the reduced frequency is 0.14, the energy harvest efficiency can reach more than 40%.

Presenting Author: Huilan Yao College of Engineering

Presenting Author Biography: Ph.D. in Ship and Ocean Engineering, currently engaged in teaching and research work at Ocean University of China, with research areas including marine propellers and oscillating hydrofoil tidal current turbines. The main research results have been published in international journals such as Fluid Physics, Ocean Engineering, and Applied Ocean Research.

Authors:

Huilan Yao College of Engineering
Boxiao Zhang College of Engineering
Xin Zhou College of Engineering