射流式鱼泵内鱼类应激状态下的运动特性及损伤机理研究

Jet fish pump is an efficient fish transport device without moving parts. However, there are complex hydraulic factors, such as shear flow and pressure gradient, in jet fish pumps and they are potential injury risks for fish. In addition, fish are stressed by them and have non-cruise behavior in jet fish pumps. Affected by the internal flow, the stressed fish has special locomotion characteristics. The trajectory and posture of fish are closely related with the injuries of fish in the jet fish pump. Numerous studies have been done on fish locomotion and fish injury caused by single hydraulic factor but the locomotion characteristics for fish under stress are ignored and the mechanism of fish injury caused by complex hydraulic factors is still not well revealed.. In this project, the locomotion characteristics for fish under stress are investigated based on the methods of theoretical analysis, numerical simulation and experimental methods. A numerical simulation method will be established to study the unsteady flow field disturbed by fish locomotion and the generation mechanism of non-cruise behavior for fish in jet fish pump will be revealed. Mechanical models of fish injuries caused by shear flow and pressure gradient will be established and the influence degree of fish injury caused by complex hydraulic factors will be analyzed to reveal the injury mechanism in jet fish pumps. The influence rules of structure and operation parameters on hydraulic factors and fish injuries will be investigated and a optimization method of jet fish pumps will be established. The present research can enrich the fundamental theory of fish behavior and injury, and can be used for reference in the study of fish-friendly hydraulic machinery.

射流式鱼泵结构简单、本身无运动部件，是高效的鱼类输送设备。但其内部存在的剪切流动和压力梯度等复杂水力因素是鱼类损伤的潜在风险。受这些因素胁迫，鱼类产生应激响应及非巡游行为，并受泵内流动影响而表现出应激状态下的运动特性，而其运动轨迹及姿态与其所受损伤密切相关。尽管国内外已对鱼游运动及单一水力因素作用下鱼类损伤展开了较多研究，但尚未考虑鱼类应激状态下的运动特性，且未能很好揭示复杂水力因素作用下的鱼类损伤机理。.本项目拟采用理论分析、试验研究和数值模拟等方法，研究泵内鱼类应激状态下的运动特性，并建立鱼类扰动作用下泵内非定常流动数值计算方法，揭示鱼类非巡游行为机理；建立剪切流动与压力梯度作用下鱼类损伤力学模型，分析泵内水力因素对鱼类损伤的影响程度，揭示鱼类损伤机理；研究泵结构及运行参数对鱼类损伤的影响规律，并建立优化方法。研究成果可完善鱼类行为与损伤基础理论，对鱼友好型水力机械研究具有借鉴意义。

射流式鱼泵具有鱼类输送损伤小、可不间断输送、结构简单、运行维护方便等诸多优点，在水产领域有着广阔的应用前景。本课题采用理论分析、实验研究和数值模拟相结合的研究方法，开展射流式鱼泵内鱼类应激状态下的运动特性及损伤机理研究，取得的主要成果如下：（1）对射流式鱼泵内鱼类的运动行为开展实验研究，得到了泵内鱼类应激状态下的运动特性；（2）对鱼类扰动下的射流式鱼泵内流体非定常流动开展数值模拟研究，发展了一种基于图像序列的无规则运动物体扰动下的非定常流动数值计算方法，并成功应用于射流式鱼泵输鱼过程的数值模拟；（3）对射流式鱼泵内复杂水力因素作用下的鱼类损伤开展研究，探究了诸如压力梯度、剪切流动和空化流动等水力因素作用下的鱼类表观及内部组织的损伤机理；（4）对射流式鱼泵开展优化研究，建立了泵结构参数与水力因素、泵效率之间的映射关系，并采用多目标遗传算法得到了兼顾高性能与低鱼损的射流式鱼泵结构。在项目执行期间，共发表基金标注论文9篇，其中SCI检索7篇，授权专利3项，博士后出站1人，培养硕士研究生4人。研究成果加深了对复杂水力因素作用下的鱼类行为与损伤机理的认识，可为解决水力机械、水工建筑等内部复杂水力因素对鱼类健康影响问题提供技术支撑，具有重要的学术价值和工程应用价值。