오리피스 U 튜브 개념에 의한 소형 부유식

Abstract

This study focuses on developing a method for analyzing a wave energy device that uses a cross-flow turbine and orifice U tube. To develop this kind of micro wave energy converter, various experimental and numerical methods are used to find and define the characteristics about wave energy converter and this performance study will be based on the baseline data of the floating wave energy converter.

The results are summarized as follows.

1. Hydraulic model tests and numerical analysis have been conducted to verify the use of the orifice instead of a small scale cross-flow turbine. The difference in error is less than 10% which was determined to be acceptable. Using this method will decrease time and financial resources needed for experimental tests.

2. Through hydraulic model test with a 6 axis acceleration sensor, the high performance operating ranges have been defined. In the high performance ranges, the reasons of high performance were defined by pitch and heave motion of floating wave energy converter.

3. From previous experiments, maximum shaft power and torque are simulated by a commercial CFD code, ANSYS CFX ver. 14. Between the pitch angles from 7 to 15 degrees, 4.9W is the maximum shaft power. in the real scale model, 15.5W of shaft power is expected by using the Froude Scale at a scale of 5.3:1.

4. This kind of the floating wave energy converter is limited because of the restricted dimension of the nozzle and turbine size. But in the chapter 4, the enlarged model shows the possibility of producing around two times of the shaft power and torque.

5. The floating wave energy converter uses only pitch motion to generate mechanical energy and high performance range are restricted. In case of the wave energy converter with heave controller, high performance range can be extended. The high rotational speed of turbine range is in 3.0 m, 4.6 m, 5.2 m of wave length.