摘要
目前中国虾夷扇贝网具存在捕捞效果差、海底生境影响严重等问题,该研究基于水下视频监控技术,设计了水压板导流与随动式惊扰相结合的拖曳网架结构。采用FLUENT软件对改造后捕捞网具的水下拖曳水动力特性进行分析得出,在拖曳水深在30~50 m、拖曳速度为1.8 m/s、网口高度为350 mm时,采用22.5°~30°负迎角弧式水压板,可减轻顶部湍流对底栖鱼类的兼捕影响,且随动式惊扰装置满足作业要求,此时拖曳稳定绳长约为156.80~261.34 m、稳定角度为11.03°、稳定拖曳力为2275.83 N。通过海上捕捞对比试验得出,在拖曳速度为1.5、1.8和2.0 m/s时,改造后捕捞网具与生产用捕捞网具在捕捞量方面无显著差异(P>0.5),在碎贝量和底栖鱼类兼捕量方面显著降低(P<0.5)。单网平均捕捞量的偏差率分别为6.30%、0.59%和5.55%,单网平均碎贝量的偏差率分别为90.63%、84.78%、85.29%,单网底栖鱼类平均兼捕量的偏差率分别为78.57%、81.25%、84.85%。且在拖曳速度为1.8 m/s时,与生产用网具相比,单网平均捕捞量偏差率最低,单网平均碎贝量的偏差率最低,底栖鱼类平均兼捕量显著减少,符合环境友好型捕捞网具设计要求。
Patinopecten yessoensis have been one of the most valuable shellfish in the North Yellow Sea.Trawling has also been one of the most widely used harvestings.However,the bycatch of benthic fish and the impact of the trawling process on the bottom ecology have posed a great threat to the sustainable development of the scallop farming industry.Eco-friendly fishing has been a high demand in recent years.It is very necessary to optimize the structure of the net gear(the disturbing device and the trawling structure)and the speed of the trawling net in the combination with the bottom of the seabed.In this study,an environment-friendly fishing optimization and transformation scheme was proposed to evaluate the performance of the disturbing device and the trawl structure for the three scallop fishing nets,such as the dredge,cutting,and hydrodynamic types.The underwater video surveillance technology was also used to clarify the causes of the problems(leakage capture,broken,and choking mud)in the underwater operation of scallop fishing nets.The gravity mesh head,torsion spring type elastic teeth/multi-strand wire rope type elastic teeth,and flexible tail trawl were transformed into the adjustable hydraulic plate mesh head structure,follow-up the disturbing device,and flexible connection of rigid tail trawl net structure.As such,there was a significant decrease in the missed catch rate,broken shell rate,sediment content,and bottom-dwelling fish bycatch.The Ansys-Fluent software was utilized to simulate the three hydraulic plates(plate,positive angle of attack arc,and negative angle of attack arc type)at four towing speeds of 1,1.5,2,and 2.5 m/s.The hydrodynamic characteristics demonstrated that the drag resistance of three hydraulic pressure plates increased with the increase of the outflow angle and the drag speed.There was less resistance of the positive angle of attack arc type and the negative angle of attack arc type hydraulic pressure plate,compared with the flat type.The negative lift generated by the hydraulic plate i
作者
李明智
何瑞麟
陈海泉
刘鹰
张光发
孙玉清
Li Mingzhi;He Ruilin;Chen Haiquan;Liu Ying;Zhang Guangfa;Sun Yuqing(Marine Engineering College,Dalian Maritime University,Dalian 116026,China;College of Navigation and Shipbuilding Engineering,Dalian Ocean University,Dalian 116023,China;College of Biosystems Engineering and Food Science,Zhejiang University,Hangzhou 310058,China;School of Mechanical Engineering,Shanghai Dianji University,Shanghai 201306,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2022年第11期21-30,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点研发计划项目(2020YFD0900700)
现代农业产业技术体系专项资金资助(CARS-49)
辽宁省教育厅科学研究项目(DL202004)。
关键词
渔业
设计
试验
捕捞网具
环境友好
数值模拟
水动力分析
fisheries
design
experimental
fishing gear
environmentally friendly
numerical simulation
hydrodynamic analysis
