LIU Zhiqiang
College of Marine Sciences, Shanghai Ocean University, Shanghai 201306 , ChinaWAN rong
College of Marine Sciences, Shanghai Ocean University, Shanghai 201306 , China ；National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai 201306 , China ；Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education ， Shanghai OceanUniversity, Shanghai 201306 , ChinaHU Fuxiang
Tokyo University of Marine Science and Technology, Tokyo 108-8477, JapanYE Yuchang
College of Marine Sciences, Shanghai Ocean University, Shanghai 201306 , China ；National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai 201306 , China ；Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education ， Shanghai OceanUniversity, Shanghai 201306 , ChinaZHOU Cheng
College of Marine Sciences, Shanghai Ocean University, Shanghai 201306 , China ；National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai 201306 , China ；Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education ， Shanghai OceanUniversity, Shanghai 201306 , ChinaLIU Zhiliang
College of Marine Sciences, Shanghai Ocean University, Shanghai 201306 , ChinaZHANG Yuanrui
Shandong Haoyuntong Nets Technology Co., Ltd., Rongcheng 264300 , ChinaS973
The sampling trawl of Quantitative sampling of larval and juvenile fish is advantageous for assessing dynamic changes in fishery resource replenishment and population numbers. It provides a basis for decisionmaking to further enhance the sustainable use of fisheries resources. In this study, a flume tank experimental method was employed to investigate the hydrodynamic performance variations of a frustum-type depressor for sampling trawls with different inclined positions (inward, outward, and tilted). Furthermore, numerical simulations using OpenFOAM were employed to analyze the alterations in the flow field around the depressor at different positions. The results showed that the sinking coefficient of the depressor initially increased and then decreased with increasing angle of attack and heel angle, and both reached their maximum values at a heel angle of 5°. The maximum values for inward and outward inclined were 1.75 and 1.77 (α=25°), respectively, and the maximum values for tilt were both 1.78 (α=25°). The drag coefficient gradually decreased with increasing heel angle and increased with increasing angle of attack. The ratio of the sinking force to drag initially increased and then decreased with increasing angle of attack and heel angle. The maximum values were reached at heel angles of 20° and 10° for inward and outward inclined, with values of 3.73 and 3.76, respectively (α=20°). The maximum values were reached at a heel angle of 5° for tilted, with values of 3.67 and 3.71, respectively (α=20°). The pressure center coefficient remains relatively constant at different angles of attack. Cpc gradually increases with increasing heel angle, while Cpb remains constant with increasing heel angle. The flow velocity on the outer side of the depressor decreased gradually as the heel angle increased. Under outward inclination, the boundary layer separation point on the depressor gradually moved toward the leading edge of the plate. In both forward and backward inclination states, the flow velocity decay region at the rear of the depressor gradually expanded as the heel angle increased. This study elucidates the hydrodynamic performance variations of the depressor under different inclination states, providing a scientific basis for further rational installation and adjustment of the working positions of the depressor.
刘志强,万荣,胡夫祥,叶旭昌,周成,刘志良,张元锐. 不同姿态下仔稚鱼采样网用台字形沉降板水动力特性[J]. Jounal of Fishery Sciences of China, 2023,[volume_no](10):1282-1291
Copy
