摘要： 鱼类的体型、游泳速度及耐流能力是其长期适应外界水生环境的进化结果。鱼在游动或水流作用下，鱼体与流体会产生复杂的相互作用，导致其消耗大量能量，对其生存和生长具有重要影响。本研究以虹鳟（Oncorhynchus mykiss）为研究对象，构建基于实物尺寸的三维数值模型，通过3D打印制作实物模型，利用水槽试验和数值模拟方法研究其水动力学特性。结果显示，在雷诺数1.6×105~5.8×105区间内，冲角0° ~ 45°范围内鱼体阻力系数CX随冲角增大从0.027增大至0.599，呈指数增长趋势，侧向力系数CY随冲角增加呈现线性增长趋势，最大达到了0.71；冲角和鱼体结构曲率对鱼体周围的流速分布具有协同影响，随着冲角的增大，速度场中高流速区和低流速区呈现一定的移动规律。鱼体结构与表面的压力分布密切相关，随着冲角的变化，鱼体不同部位出现不同的压力分布规律，随着冲角的增大，迎流面正压区占比由23.90%增长至71.66%，背流面正压区占比由23.90%减小至1.35%。研究结果可为虹鳟的个体和群体行为以及养殖水域的选择、养殖技术和装备开发以及仿生学研究提供参考。

关键词: 虹鳟, 鱼体, 水动力学特性, 水槽试验, 数值模拟

Abstract: The body shape, swimming speed, and tolerance ability to flow of fish are the evolution results of their long-term adaptation to the external aquatic environment. Under the action of swimming or water flow, fish and fluid will have complex interactions, resulting in a large amount of energy consumption, which has an important impact on their survival and growth. In this paper, rainbow trout was taken as the research object, and a three-dimensional numerical model based on physical size was constructed. The physical model was made by 3D printing, and the hydrodynamic characteristics were studied by flume experiment and numerical simulation. The results showed that in the Reynolds number range of 1.6 × 105 ~ 5.8 × 105, the fish resistance coefficient CX increased from 0.027 to 0.599 with the increase of impact angle, showing an exponential growth trend of inclinations in the range of 0° ~ 45°, and the lateral force coefficient CY showed a linear growth trend with the increase of inclinations, reaching the maximum of 0.71. Since the inclinations and the structural curvature of the fish have a synergistic effect on the flow velocity distribution around the fish, with the increase of the inclinations, the high-velocity area and the low-velocity area have a certain movement rule in the velocity field With the change of inclinations, different pressure distributions appear in different parts of fish, with the increase of the impact angle, the proportion of the positive pressure area on the stoss side increased from 23.90 % to 71.66 %, and the proportion of the positive pressure area on the slip slope decreased from 23.90 % to 1.35 %. The results can provide a reference for individual and group behaviors of rainbow trout, selection of breeding waters, development of breeding technology and equipment, and bionics research.

Key words: Rainbow trout, fish body, hydrodynamic characteristics, flume experiment, numerical simulation