CFD-CSD coupled analysis of underwater propulsion using a biomimetic fin-and-joint system
CFD-CSD coupled analysis of underwater propulsion using a biomimetic fin-and-joint system
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DOI：
10.1016/j.compfluid.2018.06.014
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发表时间：
2018-08-30
影响因子：
2.8
通讯作者：
Wang, Kevin G.
中科院分区：
文献类型：
--
作者：
Chung, Howard;Cao, Shunxiang;Wang, Kevin G.
各种鱼类在推进和机动方面的卓越表现促使人们设计和分析灵活的仿生水下推进器，这种推进器可能特别适合于小型无人驾驶飞行器。在这项工作中，我们使用一种新的流固耦合计算框架FIVER(一种基于精确黎曼解算器的有限体积法)来模拟鳍和关节系统的扑动运动，该系统模拟了鱼的尾柄和尾鳍，并作为尾主式鱼推进的简化工程模型。该问题以流固耦合为主，具有三维非定常流体流动、结构运动变形大、附加质量效应强等特点。为了应对这些挑战，我们应用嵌入式边界方法和数值稳定的划分过程来耦合有限体积有限元计算流体动力学(CFD)求解器和非线性有限元计算结构动力学(CSD)求解器。首先，利用基频、水动力和结构位移的实验数据对CFD和CSD模型进行了验证。接下来，我们研究了流体和结构动力学，以及推进性能，重点是双向流固耦合和三维流动变化，补充了现有的关于生物和生物启发的流体动力学的文献。此外，通过比较宽的梯形鳍和窄的叉形鳍，我们研究了鳍几何形状的各种影响，更广泛地说，还演示了在工程系统设计中使用观察和生物多样性知识。(C)2018爱思唯尔有限公司。保留所有权利。
The remarkable performance of various species of fish in propulsion and maneuvering has motivated the design and analysis of flexible, biomimetic underwater propulsors, which may be particularly suitable to small-scale, unmanned vehicles. In this work, we employ a novel fluid-structure coupled computational framework, referred to as FIVER (a Finite Volume method based on Exact Riemann solvers), to simulate the flapping motion of a fin-and-joint system, which mimics the caudal peduncle and caudal fin of fish, and serves as a simplified engineering model of tail-dominated fish propulsion. This problem is dominated by fluid-structure interaction, featuring a three-dimensional, unsteady fluid flow, large structural motion and deformation, and strong added-mass effect. To handle these challenges, we apply an embedded boundary method and a numerically-stable partitioned procedure to couple a hybrid finite volume finite element computational fluid dynamics (CFD) solver and a nonlinear finite element computational structural dynamics (CSD) solver. First, we validate the CFD and CSD models using experimental data in fundamental vibration frequency, hydrodynamic forces, and structural displacement. Next, we investigate the fluid and structural dynamics, as well as the propulsive performance, focusing on the two-way fluid-structure coupling and the three-dimensional flow variation, which supplements the existing body of literature on biological and bio-inspired fluid dynamics. Further, by comparing a wide, trapezoidal fin and a narrow, forked fin, we investigate the various effects of fin geometry, and more generally, also demonstrate the use of observations and knowledge of biological diversity in the design of engineering systems. (C) 2018 Elsevier Ltd. All rights reserved.