【作者】 崔勇；

【导师】 万荣；

【作者基本信息】 中国海洋大学 ， 增殖养殖工程， 2012， 博士

【摘要】 鲆鲽类网箱养殖是近年来发展起来的1种节能型生态养殖模式。由于鲆鲽鱼类的栖底习性，目前用于海上养殖的网箱多为方形平底结构，其水面框架由金属管材制成，底部配有张紧绳索的框架以支撑底部网衣。在海上养殖中，鲆鲽类网箱在水流和波浪的作用下会产生变形，特别是网箱的底部在波流的作用下极易发生倾斜、摇摆和震动，这对鲆鲽鱼类的养殖危害极大。因此，为确保网箱设施的安全和稳定，必须对波流作用下鲆鲽类网箱的水动力学特性开展研究。本论文研究依托于国家“863”计划、鲆鲽类产业技术体系和国家自然科学基金项目。本研究通过水槽模型实验的方法，分别研究鲆鲽类网箱在水流、波浪以及波流联合作用下的水动力学特性。选取了不同的网箱底框架结构、不同的网目形状与不同规格大小的网箱进行对比分析，以期为网箱结构优化设计提供理论依据。此外，在数值模拟中，本文基于ANSYS提供的参数化建模技术，利用APDL语言开发出适合于鲆鲽类网箱结构分析的专用程序，对波流场中网箱整体结构进行了动力分析。通过将水槽实验结果与模拟结果对比分析，验证了数值模拟方法的可靠性。通过研究发现：1．单纯水流作用下，网箱底框架最大倾角与迎流面锚绳最大张力均随流速的增加而增大。3种不同重量底框架的网箱迎流面锚绳最大张力随底框架重量的增加而增大。方形网目网箱的底框架最大倾角随流速增加几乎没有改变。当改变网箱规格时，大规格网箱的迎流面锚绳最大张力大于小网箱，但大规格的网箱相比小网箱具有更好的稳定性。2．单纯波浪作用下，网箱底框架最大倾角与锚绳张力随周期、波高的增加而增大。改变底框的重量对底框倾角的影响明显，且重量越大网底结构越稳定；改变网目形状对网箱的影响较明显，且综合比较方形网箱更合理；改变网箱大小对网箱的影响较明显，且综合比较大网箱更合理。在波浪作用的数值模拟中，采用线性波浪理论得到的模拟值比斯托克斯5阶波浪理论更加接近实验值。3．波流联合作用下，改变底框的重量对浮架和底框的倾角影响明显，底框越重倾角越小。改变网目形状对网箱运动受力的影响较明显，且综合比较方形网箱更合理；改变网箱大小对其运动受力的影响较明显，且综合比较大网箱更合理。其次，通过2种不同的波流相互作用模式对网箱运动受力进行了数值模拟，结果显示差别不明显。通过数值模拟还可发现，当水流入射方向与波浪成一定角度时，网箱底框架的最大倾角与迎波面锚绳最大张力均随波流夹角的增加而减小。更多还原

【Abstract】 The flatfish is one of the valuable bottom fish species. At present aquacultureproduction of flatfish mostly depends on circulating system because of their livinghabit, whereas some issues occur during the aquaculture production such as drugremnant. Recently flatfish cage aquaculture plays an increasingly important role in theflatfish production industry in China and worldwide. The configuration of flatfishcage is usually square, furthermore the surface frame of cage is made up of metal pipeand there are tight ropes in the bottom frame to hold the bottom nets. In practiceproduction the bottom component of flatfish cage will sharply incline due to highspeed ocean current and strong sea wave, moreover it results in a lot of harm to theflatfish in cage. So one of the key problem is to research the dynamic behavior of theflatfish cage under current and wave conditions for aquaculture engineering，i.e. thecage deformation should be as slight as possible to maintain balance for the flatfish incage.A series of scaled physical model tests in current and regular waves are conducted.And then the whole displacements of flatfish cage assembled support pipes in bottomframe are measured and calculated by CCD and special software. The mooring lineforces are also measured by four transducers. The APDL language provided byANSYS itself is used to develop the specific program for structural analysis of flatfishcage. And then the dynamic analysis of flatfish cage in currents and waves isconducted. Furthermore, the model test data are used to verify the validity of thesimulated results. The results show that：(1) The maximum inclination of bottom frame and the maximum values of frontmooring line force increase with increasing flow velocity in currents. And the maximum values of front mooring line force increase with increasing bottom weight.The maximum inclinations of bottom frame for cage of square mesh change lessobviously with increasing flow velocity. Moreover, the maximum values of frontmooring line force of large cage are greater than that of small cage, but the large cagehas better stability than the small cage.(2) The differences in displacement and mooring line force of flatfish cages inwaves for the three weight modes are insignificant. The maximum inclinations ofbottom frame decrease with increasing bottom weight under wave conditions. And themaximum values of front mooring line force increase with increasing bottom weight.Moreover, the maximum incline angles of bottom frame with diamond mesh arelarger than that of cage with square mesh. The tendency seems to be that thedeformation and force of flatfish cage increase with increasing wave height for thesame wave period and increase with increasing wave period for the same wave height.(3) The maximum inclination of float and bottom frame are affected by weight ofbottom frame obviously. And the heavier bottom frame is, the better stability the cagehas. The motion and load are affected by shape of mesh obviously, and the stability ofcage of square mesh is better. The motion and load are also affected by the size ofcage obviously, and the large cage is better. Then, the effect of waves and current oncage is simulated by two modes of wave-flow interaction. The results show nodifference. And the maximum inclination and front mooring line force of cagedecrease with increasing angle between wave and current.更多还原