Session: 09-08-02: Tidal Energy: Nozzles and Ducts

Submission Number: 157522

The Effect of Different Shapes of the Nozzle-Diffuser Duct Used for for an Innovative Wave Energy Conversion System 

In present study, the effect of the nozzle-diffuser duct (NDD) shape of an innovative wave energy converter is investigated numerically. To understand how the wave energy is transmitted into the flow kinetic energy inside NDD, three types of shape is probed. Firstly, the problem in present paper is explained. Next, numerical method and related schemes are briefly introduced, and validation is then carried out. After the numerical calculation result of present model is compared with other studies, the difference as a whole is observed to be less than 3%. As a result, further investigation is continued. The effect of NDD shape is then analyzed. It is revealed from the result that among three types of shapes, the saddle-like shape outperforms the other two types. The wedge-type is second to saddle-like, while the least energy is transmitted through the center of rectangular-type NDD. To evaluate the energy that flowed through NDD, the energy flux ratio is delineated. The energy flux ratios of three aforementioned cases (namely saddle-type, wedge-type and rectangular-type) are around 75%, 35% and 12%, respectively. The result, which aligns with the NDD’s characteristic applied in the context of wind or water turbines installed to garner energy, can be used to garner wave energy and to improve breakwater caisson shape for better multifunctional performance.

Presenting Author: Shing-Nan Wu Dept. of Marine Environment and Engineering

Presenting Author Biography: Ph. D. Student