A TIME-DOMAIN NUMERICAL TOOL FOR A WAVE ENERGY ATTENUATOR WITH THE SPH METHOD

Authors

Da-Wei Chen, Institute of Ocean Energy, Saga University, 1 Honjo machi, Saga-shi, Saga, Japan. Department of System Engineering and Naval Architecture, National Taiwan Ocean University, Keelung, Taiwan, R.O.C.
Shuichi Nagata, Institute of Ocean Energy, Saga University, 1 Honjo machi, Saga-shi, Saga, Japan.
Shiaw-Yih Tzang, Department of Harbor and River Engineering, National Taiwan Ocean University, Keelung, Taiwan, R.O.C.Follow
Yasutaka Imai, Institute of Ocean Energy, Saga University, 1 Honjo machi, Saga-shi, Saga, Japan.
Chih-Min Hsieh, Department of Marine Information and Technology, National Kaohsiung Marine University, Kaohsiung, Taiwan, R.O.C
Jiahn-Horng Chen, Department of System Engineering and Naval Architecture, National Taiwan Ocean University, Keelung, Taiwan, R.O.C.

Abstract

The wave energy attenuator is a floating device which operates perpendicular to the wave fronts and captures wave energy from the relative motions of two hinged floaters as waves passing by them. For establishing the time-domain numerical tools to evaluate the performance of a wave energy attenuator, a Smoothed Particle Hydrodynamic (SPH) model with mesh-free method was adopted to simulate the hydrodynamic behaviors of each floating object. Three different wave heights of 6 cm, 7 cm, and 10.4 cm of the same period of 1.22 s were commonly derived from typical potential oceanic zones offshore Taiwan and Japan. Comparisons of the hydrodynamic behaviors of an attenuator show that the device has an averaged rotating angles of about 9-15 degrees for the upstream floater (Floater A) and of smaller about 6-9 degrees for the downstream floater (Floater B) during an averaged wave cycle. For energy conversions, the wave height of 6 cm has the maximum capture factor of 22%, which is larger than those of 7 cm and 10.4 cm by about 4% and 17%, respectively. Moreover, the converted ratio by an attenuator WEC from wave energy loss are about 67% at H = 6 cm, 38% at H = 7 cm, and 19% at H = 10.4 cm, respectively.

Recommended Citation

Chen, Da-Wei; Nagata, Shuichi; Tzang, Shiaw-Yih; Imai, Yasutaka; Hsieh, Chih-Min; and Chen, Jiahn-Horng (2017) "A TIME-DOMAIN NUMERICAL TOOL FOR A WAVE ENERGY ATTENUATOR WITH THE SPH METHOD," Journal of Marine Science and Technology: Vol. 25: Iss. 6, Article 16.
DOI: 10.6119/JMST-017-1226-16
Available at: https://jmstt.ntou.edu.tw/journal/vol25/iss6/16