摘要
以S-型游动鱼作为对象,采用不可压缩Neo-Hookean材料描述鱼游动过程中的柔性变形及其与流体相互作用产生推力的自主游动特性。基于浸入边界法(IBM)的有限单元(FEM)离散模型,模拟了考虑鱼体肌肉作用力效应的柔性鱼在不可压缩粘性流体中自主游动的动力学过程,分析了流固耦合柔性鱼的游动机制及柔性变形的水弹性动力学特性。研究发现:随着鱼尾部不断呈S-型往复摆动,鱼体运动速度也呈波动形状,且受流固耦合的水动力学特性控制,并与鱼体的刚度密切相关。游动过程中,在鱼头的部位首先有涡旋形成,随着鱼向前游动,这些涡旋附着在鱼体表面向后滑移,并在鱼尾末端脱落形成S-型状的尾流。S-型状尾流直接影响鱼游动的速度及稳定性。
An S-typed flexible fish is modelled with incompressible Neo-Hookean material to describe flexible deformation of the fish body in fluid-structure interaction(FSI), in which the fish has a self-propelled motion in the direction of movement. The immersed boundary method(IBM) and the finite element method(FEM) were used to model the self-propelled flexible deformation fish with fluid-structure interaction, considering the effects of internal forces resulting from fish muscles. The study shows that the swimming speed of the fish increases fluctuantly with the constant S-shaped swing of the fish body, and the swing patterns of the fish body are based on the hydrodynamic performance of the interaction between the fish and fluid, as well as the fish body stiffness. The vortexes are firstly formed around the head of the fish, then move towards fish tail along the fish body as the fish moves forward, and finally shed from the tail in an S-shaped formation. The S-shaped wake flow directly affects the stability of the fish body and the swimming speed.
出处
《工程力学》
EI
CSCD
北大核心
2015年第5期13-18,共6页
Engineering Mechanics
基金
国家自然科学基金面上项目(51279071)
高等学校博士学科点专项科研基金(优先发展领域)项目(20135314130002)
关键词
S-型柔性鱼
超弹性柔性结构
自主游动
流固耦合
浸入边界法
S-typed flexible fish
flexible hyper-elastic structure
self-propelled swimming
fluid-structure interaction
immersed boundary method
