Experimental investigation on the hydrodynamic performance of plane nets fouled by hydroids in waves. (1st October 2020)

• Record Type: Journal Article
• Authors: Bi, Chun-Wei; Chen, Qiu-Pan; Zhao, Yun-Peng; Su, Hui; Wang, Xiang-Yu
• Is Part Of: Ocean engineering. Volume 213(2020)
• Publication Date: 2020-10-01
• Subjects: Fish cage -- Hydroid fouling -- Wave force -- Hydrodynamic coefficient -- Laboratory experiment; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2020.107839
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Biofouling of netting adversely impacts aquaculture operations and the structural safety of fish cages. In this study, the effects of the hydroids on the hydrodynamic performance of a plane net in waves were determined experimentally. A series of plane nets with various levels of biofouling was obtained via field sampling from a fish farm. The hydrodynamic force and motion response of both clean and biofouled nettings in waves were measured in a wave-current tank. The corresponding drag and inertia coefficients of the nettings were then calculated. In the studied waves, the wave force acting on the biofouled netting was as high as 3.88 times that acting on the clean netting. The maximum amplitude of the horizontal motion for the most severely biofouled netting was 3.84 times that for the clean netting. For various wave conditions, the biofouled netting drag coefficients and inertia coefficients were 3.30–7.72 and 5.04–10.83, respectively. The results indicated that netting biofouling by hydroids increases the drag force more substantially than it increases the inertial force. Highlights: Force and motion responses of hydroid-fouled nets in waves is experimentally studied. The drag and inertia coefficients of the hydroid-fouled nets are analyzed. Ratio of inertia force to drag force of both clean and biofouled nets are discussed.