Session: 05-02-02 Aquaculture and Related Technology II

Paper Number: 125531

125531 - Experimental Study of the Hydrodynamic Characteristics of the Longline Aquaculture Facilities With Oyster Cages Around a Windfarm Monopile 

This paper is based on the research about the integrated development model of Shandong Laizhou Bay marine ranching and offshore windfarm. Experimental tests were carried out to study the hydrodynamic characteristics of the longline aquaculture facilities with oyster cages. The experiments were conducted in the ocean engineering wave tank of Tokyo University, with tank dimensions of 50 m × 10 m × 5 m (length × width × height). The longline aquaculture facility model was fabricated based on the Froude similarity law with a 1/8 length scale. The water depth in the experiments was 1 m. Sigle-row (12.5 m×1, SL1) and four-row (12.5 m×4, 1, 2, 3, 4) longline aquaculture models were arranged around the windfarm monopile (with a diameter, D = 0.63 m and height, 2.0 m), with a cable depth ratio of 1:3. This study investigates the influence of the windfarm monopile on the mooring line tension and oyster cages motion response of single-row and four-row longline aquaculture models under different wave heights ( = 0.063 m, 0.1 m, 0.1125 m, 0.125 m, 0.156 m, 0.188 m) and wave periods ( =1.0 s, 1.1 s, 1.2 s, 1.237 s, 1.3 s, 1.4 s). The results show that the windfarm monopile has a significant dissipation effect on wave propagation, especially for SL1. When T = 1.0 s and H =0.1125 m, with a wind monopile, the maximum tension of the upstream mooring line is T = 1.86 N, while without a wind monopile, it is T = 8.04 N. The presence of a wind monopile on the windward face reduces the mooring line tension by 73.18-82.01% compared to the absence of a wind monopile. For four-row longline aquaculture models arranged downstream of wind monopiles, with each row spaced 1.25 m apart, under the conditions of =1 s and =0.1125 m, with a wind turbine, the maximum mooring line tensions on the upstream face are T_L1 = 3.23 N, T_L2 = 2.45 N, T_L3 = 2.74 N, T_L4 = 1.67 N, respectively. Without a wind monopile, the maximum mooring line tensions are T_L1 = 3.63 N, T_L2 = 3.14 N, T_L3 = 3.63 N, T_L4 = 2.25 N, respectively. Single-row longline aquaculture model is more significantly affected by wind monopile, while in the case of four-row longline models arranged side by side, the two middle rows are more affected by wind monopile, and there is mutual influence among them. Therefore, conducting relevant research on the hydrodynamic characteristics of offshore aquaculture facilities in offshore wind farms can provide scientific guidance for the integrated development model of marine ranching and offshore windfarm and serve as a reference for the spatial layout of offshore aquaculture facilities in offshore windfarm.

Presenting Author: Deming Chen Ocean University of China

Presenting Author Biography: Deming Chen received a B.A. in Marine Fishery Science and Technology from Ocean University of China (OUC) in 2018. I am working toward an M.A. in Fishing Science at the College of Fisheries at OUC. My research focuses on the hydrodynamic characteristics of aquaculture facilities, such as raft aquaculture facilities, and artificial reefs, based on experimental tests, and numerical simulations.

Authors:

Qing Ai China Three Gorges Renewables(Group) Co.,Ltd.Shandong Branch
Jinchao Cao Three Gorges New Energy Shandong Changyi Power Generation Co.,Ltd.
Lei Jin Three Gorges New Energy Shandong Changyi Power Generation Co.,Ltd.
Deming Chen Ocean University of China
Yanli Tang Ocean University of China
Fenfang Zhao Ocean University of China
Huaxiang Sheng Ocean University of China
Xinxin Wang Ocean University of China