摘要
鱼类以其高效灵活的游泳能力成为生物学家与仿生学研究者长期以来的重要研究对象。研究选取以尾鳍推进游泳方式的鱼类为研究对象,构建仿生鱼几何模型与运动控制模型,利用计算流体力学方法(computational fluid dynamics,CFD)结合动网格技术,对其游泳行为进行数值模拟,研究分析其尾鳍摆动的推进机理,并在此基础上通过改变尾拍频率、摆动幅值、鱼体体波波长及鱼体体型等参数,结合鱼类的突进运动、游泳方式及体型进化等生物学特性探究不同参数对鱼类游泳能力的影响规律。研究结果表明:鱼类尾鳍摆动时尾部流场中形成的反卡门涡街是推进力的主要成因;尾拍频率和摆动幅值的增加,可使鱼类在短时间内获得较高的突进速度;当λ=0.75 L,a(x)_(max)=0.1,为获得1.0 L/s的游泳速度,尾拍频率需达到2 Hz左右;鱼体摆动时体波波长(λ)的改变将引起游泳方式的变化,当λ达到0.75 L左右,鱼体可以以0.5 L/s的速度向前游动,且推进力随体波波长增加逐渐增大;细长体型鱼类相比头大身小体型鱼类游动时产生的压差阻力小,因此,在相同的尾鳍推进模式下能够获得更大的推力。本文的研究结果可以为仿生鱼水下航行器的快速性优化设计提供一定的参考。
Fish has been the important study object of biologists and bionics researchers for a long time for their efficient and flexible swimming ability.This paper selects the fish in the swimming mode of caudal fin propulsion as the study object,and the geometric model and motion control model of biomimetic fish were constructed.The Computational Fluid Dynamics(CFD)method together with dynamic grid technology was used to simulate their swimming behavior numerically and analyze the propulsion mechanism of the caudal fin swing.On this basis,by changing the parameters such as the tail beat frequency,swing amplitude,body wave length and body shape,combined with biological characteristics such as fish’s dash movement,swimming style and body shape evolution,the influence on the swimming ability of fish under different parameters was explored.The results show that the reverse Kármán vortex street generated in the tail flow field when they move is the main cause of the propulsion force.With the increase of tail beat frequency and swing amplitude,fish can get a higher dash speed in a short time.Whenλ=0.75 L,a(x)_(max)=0.1,in order to obtain the swimming speed of 1.0 L/s,the tail beat frequency should reach about 2 Hz.The change of body wave length(λ)will change their swimming mode.When the wave length reaches about 0.75 L,the fish can swim forward at a speed of 0.5 L/s,and the propulsion increases with the increase of body wave length.Compared with fish with large head and small body,fish with slender body have less pressure difference resistance when swimming,so they can obtain greater thrust in the same caudal fin propulsion mode.The research results of this paper can provide some reference for the optimization design of the bionic underwater vehicle.
作者
初文华
员庆
孔祥洪
张忠
李浩然
钱卫国
CHU Wenhua;YUN Qing;KONG Xianghong;ZHANG Zhong;LI Haoran;QIAN Weiguo(College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,China;National Engineering Research Center for Oceanic Fisheries,Shanghai 201306,China;Key Laboratory of Sustainable Exploitation,Ministry of Agriculture and Rural Affairs,Shanghai 201306,China;School of Fishery,Zhejiang Ocean University,Zhoushan 316000,Zhejiang,China)
出处
《上海海洋大学学报》
CAS
CSCD
北大核心
2022年第5期1224-1234,共11页
Journal of Shanghai Ocean University
基金
国家自然科学基金(31972845)
国家远洋渔业工程技术研究中心开放基金(A1-2006-21-200208)
上海海洋大学科技发展专项基金(A2-2006-22-200214)。
关键词
鱼类
推进机理
游泳能力
影响参数
数值模拟
fish
propulsion mechanism
swimming ability
influencing parameters
numerical simulation
