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.

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.

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.

Dynamics of a Free Heaving and Prescribed Pitching Hydrofoil in a Turbulent Flow, With a Fluid-Structure Interaction Approach

2018 ◽  
Author(s):  
P. Brousseau ◽  
M. Benaouicha ◽  
S. Guillou
Keyword(s):  
Fluid Structure Interaction ◽  
Vertical Displacement ◽  
Rotational Displacement ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction ◽  
Maximum Angle ◽  
High Maximum ◽  
Oscillating Foil ◽  
Interaction Approach

This paper deals with the dynamics of an oscillating foil, describing a free heaving (vertical displacement) and prescribed pitching (rotational displacement) movement which is computed from its position in two different ways. A fluid-structure interaction approach is chosen, as the physics of the flow and the structure are strongly coupled. The flow is unsteady, turbulent and incompressible. The pressure/velocity problem is solved using SIMPLEC scheme. First, the pitching movement is considered as a given continuous function of the hydrofoil heaving position. Second, the pitching motion is performed alternately at the end of each heave cycle. For each case, two maximum angles of attack and one heaving amplitudes are studied. Preliminary results showed that a high maximum angle of attack generates more lift hydrodynamics force, but also requires more energy to perform the rotation of pitch.

scholarly journals Study on Fluid-Structure Interaction of Flexible Membrane Structures in Wind-Induced Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fangjin Sun ◽  
Donghan Zhu ◽  
Tiantian Liu ◽  
Daming Zhang
Keyword(s):  
Projection Method ◽  
Fluid Structure Interaction ◽  
Initial Pressure ◽  
Projection Methods ◽  
Accurate Solution ◽  
Membranous Structure ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction ◽  
Modified Projection Method

A strongly coupled monolithic method was previously proposed for the computation of wind-induced fluid-structure interaction of flexible membranous structures by the authors. How to obtain the accurate solution is a key issue for the strongly coupled monolithic method. Projection methods are among the commonly used methods for the coupled solution. In the work here, to impose initial pressure boundary conditions implicitly defined in the original momentum equations in classical projection methods when dealing with large-displacement of membranous structures, a modified factor is introduced in corrector step of classical projection methods and a new modified projection method is obtained. The solution procedures of the modified projection method aimed at strongly coupled monolithic equations are given, and the related equations are derived. The proposed method is applied to the computation of a two-dimensional fluid-structure interaction benchmark case and wind-induced fluid-structure interaction of a three-dimensional flexible membranous structure. The performance and efficiency of the modified projection method are evaluated. The results show that the modified projection methods are valid in the computation of wind-induced fluid-structure interaction of flexible membranous structures, with higher accuracy and efficiency compared with traditional methods. The modified value has little effects on the computation results whereas iteration times has significant effects. Computation accuracy can be improved greatly by increasing iteration times with less increase in computation time and little effects on stability with the modified projection method.

Scalability study of an implicit solver for coupled fluid-structure interaction problems on unstructured meshes in 3D

2016 ◽  
Vol 32 (2) ◽  
pp. 207-219 ◽  
Author(s):  
Fande Kong ◽  
Xiao-Chuan Cai
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Coupled System ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Krylov Method ◽  
Fine Mesh ◽  
Processor Cores ◽  
Fully Coupled

Fluid-structure interaction (FSI) problems are computationally very challenging. In this paper we consider the monolithic approach for solving the fully coupled FSI problem. Most existing techniques, such as multigrid methods, do not work well for the coupled system since the system consists of elliptic, parabolic and hyperbolic components all together. Other approaches based on direct solvers do not scale to large numbers of processors. In this paper, we introduce a multilevel unstructured mesh Schwarz preconditioned Newton–Krylov method for the implicitly discretized, fully coupled system of partial differential equations consisting of incompressible Navier–Stokes equations for the fluid flows and the linear elasticity equation for the structure. Several meshes are required to make the solution algorithm scalable. This includes a fine mesh to guarantee the solution accuracy, and a few isogeometric coarse meshes to speed up the convergence. Special attention is paid when constructing and partitioning the preconditioning meshes so that the communication cost is minimized when the number of processor cores is large. We show numerically that the proposed algorithm is highly scalable in terms of the number of iterations and the total compute time on a supercomputer with more than 10,000 processor cores for monolithically coupled three-dimensional FSI problems with hundreds of millions of unknowns.

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