Fluid-Structure Interaction Analysis of a Soft Robotic Fish Using Piezoelectric Fiber Composite

2014 ◽  
Vol 26 (5) ◽  
pp. 638-648 ◽  
Author(s):  
Wenjing Zhao ◽  
◽  
Aiguo Ming ◽  
Makoto Shimojo ◽  
Yohei Inoue ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Fluid Structure Interaction ◽  
Robotic Fish ◽  
Hydrodynamic Performance ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Analysis Scheme ◽  
Piezoelectric Fiber Composite ◽  
Surrounding Fluid ◽  
Piezoelectric Fiber

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00260005/13.jpg"" width=""300"" />Model of soft robotic fish</div> Designing a high-performance soft robotic fish requires considering the interaction between the flexible robot structure and surrounding fluid. This paper introduces fluid-structure interaction (FSI) analysis used to enhance the hydrodynamic performance of soft robotic fish using piezoelectric fiber composite (PFC) as the propulsion actuator. The basic FSI analysis scheme for soft robotic fish is presented, then the numerical model of the actuator, robot structure, and surrounding fluid are described based on the FSI analysis scheme. The FSI analysis of the soft robotic fish is performed through these numerical models. To evaluate the effectiveness of FSI analysis, coupling simulation and experimental results are compared. We found that the calculated results of propulsive force and deformation displacement were similar to those for experiments. These results suggest that FSI analysis is useful and is applicable to evaluating propulsion characteristics of the soft robotic fish to improve performance. </span>

Optimization of Vibration Reduction in a Helicopter Blade With 2 Way Fluid-Structure Interaction

2018 ◽  
Author(s):  
Mürüvvet Sinem Sicim ◽  
Metin Orhan Kaya
Keyword(s):  
Cantilever Beam ◽  
Fiber Orientation ◽  
Structural Model ◽  
Fiber Composite ◽  
Vibration Reduction ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Helicopter Blade ◽  
Structure Interaction ◽  
Blade Model

The main goal of this study is the optimization of vibration reduction on helicopter blade by using macro fiber composite (MFC) actuator under pressure loading. Due to unsteady aerodynamic conditions, vibration occurs mainly on the rotor blade during forward flight and hover. High level of vibration effects fatigue life of components, flight envelope, pleasant for passengers and crew. In this study, the vibration reduction phenomenon on helicopter blade is investigated. 3D helicopter blade model is used to perform the aeroelastic behavior of a helicopter blade. Blade design is created by Spaceclaim and finite element analysis is conducted by ANSYS 19.0. Generated model are solved via Fluent by using two-way fluid-solid coupling analysis, then the analyzed results (all aerodynamic loads) are directly transferred to the structural model. Mechanical results (displacement etc.) are also handed over to the Fluent analysis by helping fluid-structure interaction interface. Modal and harmonic analysis are performed after FSI analysis. Shark 120 unmanned helicopter blade model is used with NACA 23012 airfoil. The baseline of the blade structure consists of D spar made of unidirectional Glass Fiber Reinforced Polymer +45°/−45° GFRP skin. MFC, which was developed by NASA’s Langley Research Center for the shaping of aerospace structures, is applied on both upper and lower surfaces of the blade to reduce the amplitude in the twist mode resonant frequency. D33 effect is important for elongation and to observe twist motion. To foresee the behavior of the MFC, thermo-elasticity analogy approach is applied to the model. Therefore, piezoelectric voltage actuation is applied as a temperature change on ANSYS. The thermal analogy is validated by using static behavior of cantilever beam with distributed induced strain actuators. Results for cantilever beam are compared to experimental results and ADINA code results existing in the literature. The effects of fiber orientation of MFC actuator and applied voltage on vibration reduction on helicopter blade are represented. The study shows that torsion mode determines the optimum placement of actuators. Fiber orientation of the MFC has few and limited influences on results. Additionally, the voltage applied on MFC has strong effects on the results and they must be selected according to applied model.

A Study on Fluid-Structure Interaction Performance of a Flexible Hydrofoil

2018 ◽  
Author(s):  
Zheng Huang ◽  
Ying Xiong ◽  
Ye Xu ◽  
Shancheng Li
Keyword(s):  
Center Of Pressure ◽  
Separation Bubble ◽  
Fluid Structure Interaction ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Hydrodynamic Performance ◽  
Fluid Structure ◽  
Maximum Deformation ◽  
Structure Interaction ◽  
Turbulent Transition

To research the flexible hydrofoils’ hydroelastic response, the fluid-structure interaction (FSI) characteristic investigation is conducted on the basis of the analysis of a rigid hydrofoil’s hydrodynamic performance. For a rigid cantilevered rectangular hydrofoil, the pitching hydrodynamic performance is calculated using boundary motion with remeshing strategy. The Laminar Separation Bubble (LSB) and turbulent transition are captured. Numerical flow analysis revealed that the LSB occurs at 0.8c when pitching at initial angle of attack. As the angle increases to 5.1°, the laminar to turbulent transition occurs and the lift presents an inflection. For a geometric equivalent flexible hydrofoil, the static FSI characteristic is researched using oneway and two-way FSI method. The lift decreases and the drag increases using two-way compared to one-way FSI. The center of pressure and the maximum deformation move from trailing edge to leading edge as the angle of attack increases, showing the necessary of two-way FSI calculation. The transient FSI characteristic of the flexible hydrofoil is then studied using LES model. The lift fluctuation at 8° in frequency domain is calculated . The dry mode and wet mode natural frequency of the flexible hydrofoil are calculated to simulate the vibration performance, which meet the experiment data quite well, laying foundation for further research on the hydroelastic vibration response.

scholarly journals Dissipative Coupling of Fluid and Immersed Objects for Modelling of Cells in Flow

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Martin Bušík ◽  
Martin Slavík ◽  
Ivan Cimrák
Keyword(s):  
Friction Coefficient ◽  
Fluid Structure Interaction ◽  
Slip Boundary Condition ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Slip Boundary ◽  
Mesh Density ◽  
Proper Values ◽  
Surrounding Fluid

Modelling of cell flow for biomedical applications relies in many cases on the correct description of fluid-structure interaction between the cell membrane and the surrounding fluid. We analyse the coupling of the lattice-Boltzmann method for the fluid and the spring network model for the cells. We investigate the bare friction parameter of fluid-structure interaction that is mediated via dissipative coupling. Such coupling mimics the no-slip boundary condition at the interface between the fluid and object. It is an alternative method to the immersed boundary method. Here, the fluid-structure coupling is provided by forces penalising local differences between velocities of the object’s boundaries and the surrounding fluid. The method includes a phenomenological friction coefficient that determines the strength of the coupling. This work aims at determination of proper values of such friction coefficient. We derive an explicit formula for computation of this coefficient depending on the mesh density assuming a reference friction is known. We validate this formula on spherical and ellipsoidal objects. We also provide sensitivity analysis of the formula on all parameters entering the model. We conclude that such formula may be used also for objects with irregular shapes provided that the triangular mesh covering the object’s surface is in some sense uniform. Our findings are justified by two computational experiments where we simulate motion of a red blood cell in a capillary and in a shear flow. Both experiments confirm our results presented in this work.

Numerical Fluid-Structure Interaction Analysis for a Flexible Marine Propeller Using Co-Simulation Method

2021 ◽  
Vol 163 (A2) ◽  
Author(s):  
A Kumar ◽  
R Vijayakumar ◽  
VA Subramanian
Keyword(s):  
Carbon Fibre ◽  
Interaction Analysis ◽  
Fibre Composite ◽  
Fluid Structure Interaction ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Marine Propeller ◽  
Carbon Fibre Composite ◽  
Fluid Structure ◽  
Structure Interaction

Carbon fibre composite has exceptionally high strength, low density and corrosion resistance in the marine environment compared to conventional materials. These characteristics make it a favourable alternative material to be considered for manufacturing marine screw propellers. Despite these advantages, the flexibility of the material leads to a significant change in blade geometry due to loads acting on blades which alter hydrodynamic performance. A two-way coupled fluid-structure interaction analysis is required to accurately capture its hydrodynamic performance due to the reduced stiffness and material anisotropy. The present study focuses on numerical investigation for the hydro-elastic based performance analysis of a composite marine propeller in open water condition. The procedure involves the coupling of Reynolds-Averaged Navier-Stokes Equation based computational fluid dynamics solver with the finite element method solver using co-simulation technique. The open water characteristics, including thrust coefficient, torque coefficient and open water efficiency, are discussed as a function of advance ratio. This paper presents a comparison of the hydrodynamic performance and structural responses between a carbon fibre composite propeller and a conventional steel propeller which are geometrically identical. The results for the composite propeller show a significant improvement in hydrodynamic performance compared to the metallic propeller while remaining structurally safe throughout the tested range.

scholarly journals Fluid-Structure Interaction Effects on the Propulsion of an Flexible Composite Monofin

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Adil El Baroudi ◽  
Fulgence Razafimahery
Keyword(s):  
Finite Element Method ◽  
Natural Frequencies ◽  
Fluid Structure Interaction ◽  
Water Environment ◽  
Interaction Model ◽  
Added Mass ◽  
Propulsive Efficiency ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Surrounding Fluid

Finite element method has been used to analyze the propulsive efficiency of a swimming fin. Fluid-structure interaction model can be used to study the effects of added mass on the natural frequencies of a multilayer anisotropic fin oscillating in a compressible fluid. Water by neglecting viscidity effects has been considered as a surrounding fluid and the frequency response of the fin has been compared with that of vacuum conditions. It has been shown that because of the added mass effects in water environment, the natural frequencies of the fin decrease.

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