Force Analysis of IPMC Actuated Fin and Wing Assembly of a Micro Scanning Device through Two-Way Fluid Structure Interaction Approach

2015 ◽  
Vol 21 ◽  
pp. 19-32
Author(s):  
Mazhar Ul Haq ◽  
Zhao Gang ◽  
Zhuang Zhi Sun ◽  
S.M. Aftab
Keyword(s):  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Hydrodynamic Forces ◽  
Force Analysis ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Scanning Device ◽  
Drag Forces ◽  
Lift And Drag ◽  
Interaction Approach

In this paper, a methodology is presented to perform force analysis of wing and fin assembly of a micro fish like device through strongly coupled two-way fluid structure interaction approach. The scanning device operates underwater and is towed by a surface vessel through a tow cable. Device fins are actuated by ionic polymer metal composite (IPMC) actuators, an EAP actuator. Fins act as riser, depressor and stabiliser against roll motion of the device. During tow, wing and fin assembly of the device come under hydrodynamic forces. These forces are influenced by fin displacement under IPMC actuation and wing's angle of attack for same towing conditions. To fully investigate wing and fin assembly performance, we must consider the interaction between their structure and fluid (water) and model the coupling mechanism accurately for fluid structure interaction (FSI) analysis. To obtain an accurate prediction to the hydrodynamic forces on wing and fin assembly of the device, it is necessary to conduct dynamic analysis of the surrounding fluid by computational fluid dynamics (CFD). A numerical simulation of three dimensional model of the assembly is performed in ANSYS WORKBENCH by coupling transient structural and Fluid Flow (CFX) analysis systems. The objectives of this study are as follows: 1) To build an accurate three-dimensional CFD model of the wing and IPMC actuated fin 2) To quantify the lift and drag forces acting on the wing and their corresponding coefficients 3) To demonstrate the influence of wing's angle of attack and fin displacement on generation of lift and drag forces. The presented methodology is also applicable to self-propelled micro robots.

Numerical Investigation of Hydroelastic Response of a Three-Dimensional Deformable Hydrofoil

2020 ◽  
Author(s):  
Saeed Hosseinzadeh ◽  
Kristjan Tabri
Keyword(s):  
Pressure Coefficient ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Leading Edge ◽  
Elastic Response ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction ◽  
Lift And Drag ◽  
Hydroelastic Response

The present study is concerned with the numerical simulation of Fluid-Structure Interaction (FSI) on a deformable three-dimensional hydrofoil in a turbulent flow. The aim of this work is to develop a strongly coupled two-way fluid-structure interaction methodology with a sufficiently high spatial accuracy to examine the effect of turbulent and cavitating flow on the hydroelastic response of a flexible hydrofoil. A 3-D cantilevered hydrofoil with two degrees-of-freedom is considered to simulate the plunging and pitching motion at the foil tip due to bending and twisting deformation. The defined problem is numerically investigated by coupled Finite Volume Method (FVM) and Finite Element Method (FEM) under a two-way coupling method. In order to find a better understanding of the dynamic FSI response and stability of flexible lifting bodies, the fluid flow is modeled in the different turbulence models and cavitation conditions. The flow-induced deformation and elastic response of both rigid and flexible hydrofoils at various angles of attack are studied. The effect of three-dimension body, pressure coefficient at different locations of the hydrofoil, leading-edge and trailing-edge deformation are presented and the results show that because of elastic deformation, the angle of attack increases and it lead to higher lift and drag coefficients. In addition, the deformations are generally limited by stall condition and because of unsteady vortex shedding, the post-stall condition should be considered in FSI simulation of deformable hydrofoil. To evaluate the accuracy of the numerical model, the present results are compared and validated against published experimental data and showed good agreement.

Torque Analysis of IPMC Actuated Fin of a Micro Fish like Device Using Two-Way Fluid Structure Interaction Approach

2015 ◽  
Vol 25 ◽  
pp. 25-38
Author(s):  
Mazhar Ul Haq ◽  
Zhao Gang ◽  
Zhuang Zhi Sun ◽  
S.M. Aftab
Keyword(s):  
Numerical Simulation ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Pressure Profile ◽  
Three Dimensional Model ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Forces ◽  
Flow Speeds ◽  
Interaction Approach

In this paper, a numerical simulation of three dimensional model of IPMC actuated fin of a fish like micro device is presented using two-way fluid structure interaction approach. The device is towed by the surface vessel through a tow cable. Fin is acting as dorsal fin of the fish to control depth of the device and also acts as a stabiliser against its roll motion. Fin's displacement disturbs water flow streamlines around it, as a result velocity and pressure profile of fluid's domain changes around the actuated fin. As fin's position continuously changes throughout its actuation cycle, this makes it transient structural problem coupled with a fluid domain. Fin's displacement is received by the fluid and resulting fluid forces are received by the fin making it a two-way fluid structure interaction (FSI) problem. Such problems are solved by multi field numerical simulation approach. This multifield numerical simulation is performed in ANSYS WORKBENCH by coupling transient structural and Fluid Flow (CFX) analysis systems. It is desirous to determine the torque acting on the fin due to fluid forces through its actuation cycle by IPMC actuators. The objective of this study is to develop the methodology (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the IPMC actuated fin, subjected to large displacement against different flow speeds. Efficacy of fin as depressor and riser is also required to be judged by monitoring the forces acting on wing in response to its displacement under IPMC actuation. Same approach is also applicable to the self-propelled systems.

scholarly journals Investigations of aerodynamic drag forces during structural blade testing using high fidelity fluid-structure interaction

2019 ◽  
Author(s):  
Christian Grinderslev ◽  
Federico Belloni ◽  
Sergio González Horcas ◽  
Niels N. Sørensen
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Test Facility ◽  
High Fidelity ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Drag Forces

Abstract. Aerodynamic loads on wind turbine blades that are tested for fatigue certifications, need to be known for planning and defining test loads beforehand. It is known that the aerodynamic forces, especially drag, are different for tests and operation, due to the entirely different flow conditions. In test facilities, a vibrating blade will move in and out of its own wake increasing the drag forces on the blade. This is not the case in operation. To study this special aerodynamic condition present during experimental tests, numerical simulations of a wind turbine blade during pull-release tests were conducted. High fidelity three dimensional computational fluid dynamics methods were used throughout the simulations. By this, the fluid mechanisms and their impact on the moving blade are clarified and through the coupling with a structural solver, the fluid-structure interaction is studied. Results are compared to actual measurements from experimental tests, verifying the approach. It is found that the blade experiences a high drag due to its motion towards its own whirling wake, resulting in an effective drag coefficient of approximately 5.3 for the 90 degree angle of attack. This large drag coefficient was implemented in a fatigue test load simulation, resulting in a significant decrease of moment along the blade, leading to less load applied than intended. The confinement from the test facility did not impact this specific test setup, but simulations with longer blades could possibly yield different conclusions. To the knowledge of the authors, this investigation including three dimensional effects, structural coupling and confinement is the first of its kind.

scholarly journals Investigations of aerodynamic drag forces during structural blade testing using high-fidelity fluid–structure interaction

2020 ◽  
Vol 5 (2) ◽  
pp. 543-560 ◽  
Author(s):  
Christian Grinderslev ◽  
Federico Belloni ◽  
Sergio González Horcas ◽  
Niels Nørmark Sørensen
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Test Facility ◽  
High Fidelity ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Drag Forces

Abstract. Aerodynamic loads need to be known for planning and defining test loads beforehand for wind turbine blades that are tested for fatigue certifications. It is known that the aerodynamic forces, especially drag, are different for tests and operation, due to the entirely different flow conditions. In test facilities, a vibrating blade will move in and out of its own wake, increasing the drag forces on the blade. This is not the case in operation. To study this special aerodynamic condition present during experimental tests, numerical simulations of a wind turbine blade during pull–release tests were conducted. High-fidelity three-dimensional computational fluid dynamics methods were used throughout the simulations. In this way, the fluid mechanisms and their impact on the moving blade are clarified, and through the coupling with a structural solver, the fluid–structure interaction is studied. Results are compared to actual measurements from experimental tests, verifying the approach. It is found that the blade experiences a high drag due to its motion towards its own whirling wake, resulting in an effective drag coefficient of approximately 5.3 for the 90∘ angle of attack. This large drag coefficient was implemented in a fatigue test load simulation, resulting in a significant decrease in bending moment along the blade, leading to less load being applied than intended. The confinement from the test facility did not impact this specific test setup, but simulations with longer blades could possibly yield different conclusions. To the knowledge of the authors, this investigation, including three-dimensional effects, structural coupling and confinement, is the first of its kind.

Modeling of aortic valve stenosis using fluid-structure interaction method

Perfusion ◽  
2021 ◽  
pp. 026765912199854
Author(s):  
Mohammad Javad Ghasemi Pour ◽  
Kamran Hassani ◽  
Morteza Khayat ◽  
Shahram Etemadi Haghighi
Keyword(s):  
Blood Flow ◽  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Relaxation Phase ◽  
Exercise Condition ◽  
Time Dependent Domain ◽  
Comparison Of The Results

Background and objectives: Fluid structure interaction (FSI) is defined as interaction of the structures with contacting fluids. The aortic valve experiences the interaction with blood flow in systolic phase. In this study, we have tried to predict the hemodynamics of blood flow through a normal and stenotic aortic valve in two relaxation and exercise conditions using a three-dimensional FSI method. Methods: The aorta valve was modeled as a three-dimensional geometry including a normal model and two others with 25% and 50% stenosis. The geometry of the aortic valve was extracted from CT images and the models were generated by MMIMCS software and then they were implemented in ANSYS software. The pulsatile flow rate was used for all cases and the numerical simulations were conducted based on a time-dependent domain. Results: The obtained results including the velocity, pressure, and shear stress contours in different systolic time sequences were explained and discussed. The maximum blood flow velocity in relaxation phase was obtained 1.62 m/s (normal valve), 3.78 m/s (25% stenosed valve), and 4.73 m/s (50% stenosed valve). In exercise condition, the maximum velocities are 2.86, 4.32, and 5.42 m/s respectively. The maximum blood pressure in relaxation phase was calculated 111.45 mmHg (normal), 148.66 mmHg (25% stenosed), and 164.21 mmHg (50% stenosed). However, the calculated values in exercise situation were 129.57, 163.58, and 191.26 mmHg. The validation of the predicted results was also conducted using existing literature. Conclusions: We believe that such model are useful tools for biomechanical experts. The further studies should be done using experimental data and the data are implemented on the boundary conditions for better comparison of the results.

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