To adapt to the change of aquaculture workshop site,optimize the shape of aquaculture tanks and improve the utilization rate of breeding space,it is necessary to determine the appropriate length width ratio parameters...To adapt to the change of aquaculture workshop site,optimize the shape of aquaculture tanks and improve the utilization rate of breeding space,it is necessary to determine the appropriate length width ratio parameters of aquaculture tanks.In this paper,computational fluid dynamics(CFD)technology is adopted to study the flow field performance of aquaculture tanks with different L/B ratios(L:the length;B:the width,of aquaculture tank)and different jet direction conditions(lengthways jet and widthways jet).A three-dimensional numerical calculation model of turbulence in rounded rectangle aquaculture tanks in dual-diagonal-inlet layout was established.Jet directions are arranged lengthways and widthways,and the water flow velocity,resistance coefficient change,vorticity,etc.are analyzed under two working conditions.Results show that the flow field performance in aquaculture tank decreases with the increase of the L/B ratio.The flow field performed well when L/B was 1.0-1.3,sharply dropped at 1.4-1.6,and poor at 1.7-1.9.The results provided a theoretical basis for the design and optimization in flow field performance of the industrialized circulating aquaculture tanks.展开更多
在水产养殖中,准确测量养殖鱼类的体长和体宽是评估养殖质量的关键。现有测量大多具有侵入性,不仅耗费人力物力,而且会对鱼类造成伤害。对此,提出一种基于YOLO(You Only Look Once)v8和双目视觉的养殖鱼类体长体宽在线测量系统。利用YOL...在水产养殖中,准确测量养殖鱼类的体长和体宽是评估养殖质量的关键。现有测量大多具有侵入性,不仅耗费人力物力,而且会对鱼类造成伤害。对此,提出一种基于YOLO(You Only Look Once)v8和双目视觉的养殖鱼类体长体宽在线测量系统。利用YOLO v8检测双目相机拍摄的图像中的鱼体及关键点,通过最近欧几里得距离匹配关键点,计算三维空间坐标,从而实现养殖鱼类体长体宽测量。试验结果表明,在线测量系统总体平均测量误差为15.55 mm,总体误差标准差为16.47 mm,即使在鱼体交叉重叠的情况下也能实现准确测量。这一在线测量系统为水产养殖水下环境的鱼类体长体宽非接触监测提供了一种精度足够、低成本、易部署的解决方案。展开更多
基金Supported by the National Natural Science Foundation of China(No.31872609)the Innovation Support Program for High-level Talents of Dalian City(No.2019RD12)+1 种基金the Key Research Project of Liaoning Provincial Department of Education in 2022(No.LJKZZ 20220091)the earmarked fund for CARS-49(CARS-49)。
文摘To adapt to the change of aquaculture workshop site,optimize the shape of aquaculture tanks and improve the utilization rate of breeding space,it is necessary to determine the appropriate length width ratio parameters of aquaculture tanks.In this paper,computational fluid dynamics(CFD)technology is adopted to study the flow field performance of aquaculture tanks with different L/B ratios(L:the length;B:the width,of aquaculture tank)and different jet direction conditions(lengthways jet and widthways jet).A three-dimensional numerical calculation model of turbulence in rounded rectangle aquaculture tanks in dual-diagonal-inlet layout was established.Jet directions are arranged lengthways and widthways,and the water flow velocity,resistance coefficient change,vorticity,etc.are analyzed under two working conditions.Results show that the flow field performance in aquaculture tank decreases with the increase of the L/B ratio.The flow field performed well when L/B was 1.0-1.3,sharply dropped at 1.4-1.6,and poor at 1.7-1.9.The results provided a theoretical basis for the design and optimization in flow field performance of the industrialized circulating aquaculture tanks.
