Session: VIB-04-01: Energy Harvesting I

Paper Number: 91199

91199 - Preliminary Modeling of Angle of Attack in Self-Rectifying Turbine Under High Rotational Speed 

Wave energy has the potential to contribute significant parts to the future energy system. Various Wave Energy Converters(WECs) have been proposed, modeled, and tested to harvest wave energy. However, to date, none of the proposed works have been used commercially. Here, we present a modelling of a cyclorotor type WEC with adjustable pitch angle. The angle of attack is  optimized within the controllable range to maintain the largest tangential force according to the total relative velocity direction. Instead of following a frequency matching between the cyclorotor and the wave, results show that higher rotational speed of the cyclorotor can significantly increase the output power.

In this study, a 3-balde cyclorotor for wave energy harvesting is investigated based on linear wave theory through modeling and simulation. And the pitch angle of the hydrofoil is controlled to reach the maximum tangential force, which can be concluded as: 1) The self-rectifying turbine is mechanically modeled based on the Newton's Second Law, where the hydrofoil is expected to maintain the maximum tangential force under the relative velocity direction when applying the optimized angle of attack.
2) The optimized angle of attack and other pitch angles of the chosen hydrofoil shape under waves are obtained based on the simulation results. Moreover, the force and output power under the optimized conditions is further discussed. High rotational speed (n larger than 1) shows great force and power increase, which can potentially contributes to a huge improvement to the WEC concept. 

Presenting Author: xian wu Virginia Tech

Presenting Author Biography: Xian Wu is a Ph.D. student from Virginia Tech under the guidance of Prof. Lei Zuo. His current study focuses on wave-powered desalination. He got his MS degree from University of California, San Diego and Bachelor degree from Zhejiang University, China.

Authors:

xian wu Virginia Tech
Lei Zuo Virginia tech