Numerical study on hydrodynamic effect of flexibility in a self-propelled plunging foil | |
Zhu XJ(朱晓珏); He GW(何国威); Zhang X(张星) | |
Source Publication | Computers & Fluids |
2014-05 | |
Volume | 97Pages:1-20 |
ISSN | 0045-7930 |
Abstract | The present study is a numerical investigation of the hydrodynamic effects of passive flexibility ona selfpropelled plunging foil. In the model problem, the flow is two-dimensional, incompressible and laminar, while the flexible foil is treated as an inextensible filament. The leading-edge of the foil undergoes a prescribed harmonic oscillation in the vertical direction. Inthe horizontal direction, the foil is free to move and no constraint is imposed. The simulations are performed by using a solver which couples the immersed boundary method for the flow and the finite difference method for the structure. A systematic parametric study has been conducted to investigate the effects of flexibility on important physical quantities such as the cruising speed, swimmingpower and propulsive efficiency. It is found that optimal cruising speed is always achieved in foilswith some passive flexibility and not the rigid ones. Another important finding is that optimum performance is always achieved at a forcing frequencymuch lower than the resonance point. Based on the simulation results, three dynamical states of a self-propelled foil have been identified with the increase of bending rigidity, i.e., non-periodic movement, periodic backward-movement and periodic forward-movement. For a flexible foil in forward movement, depending on the range of bending rigidity, either a deflected or a symmetric vortex street arises as the characteristic wake structure. It is found that moderate flexibility is beneficial to symmetry preservation in the wake, while excessive flexibility can trigger symmetry-breaking. The results obtained in the current work shed some light onthe role of flexibility in flapping-based biolocomotion. |
Keyword | Fluid–structure Interaction Passive Flexibility Self-propulsion Plunging Foil Immersed Boundary Method Vortex Street |
Subject Area | 流体力学 |
URL | 查看原文 |
Indexed By | SCI ; EI |
Language | 英语 |
WOS ID | WOS:000337200500001 |
Funding Organization | CAS (KJCX-SW-L08) , (KJCX3-SYW-S01); NSFC (10702074), (10872201), (11023001), (11372331). |
Department | LNM湍流 |
Classification | 二类/Q2 |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/48738 |
Collection | 非线性力学国家重点实验室 |
Corresponding Author | Zhang X(张星) |
Recommended Citation GB/T 7714 | Zhu XJ,He GW,Zhang X. Numerical study on hydrodynamic effect of flexibility in a self-propelled plunging foil[J]. Computers & Fluids,2014,97:1-20. |
APA | 朱晓珏,何国威,&张星.(2014).Numerical study on hydrodynamic effect of flexibility in a self-propelled plunging foil.Computers & Fluids,97,1-20. |
MLA | 朱晓珏,et al."Numerical study on hydrodynamic effect of flexibility in a self-propelled plunging foil".Computers & Fluids 97(2014):1-20. |
Files in This Item: | Download All | |||||
File Name/Size | DocType | Version | Access | License | ||
Zhu_He_Zhang_CAF2014(4796KB) | 开放获取 | License | View Download |
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment