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.

scholarly journals Three-Dimensional Simulation of Fluid–Structure Interaction Problems Using Monolithic Semi-Implicit Algorithm

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 94 ◽  
Author(s):  
Cornel Marius Murea
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Arbitrary Lagrangian Eulerian ◽  
Time Step ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dimensional Simulation ◽  
Updated Lagrangian

A monolithic semi-implicit method is presented for three-dimensional simulation of fluid–structure interaction problems. The updated Lagrangian framework is used for the structure modeled by linear elasticity equation and, for the fluid governed by the Navier–Stokes equations, we employ the Arbitrary Lagrangian Eulerian method. We use a global mesh for the fluid–structure domain where the fluid–structure interface is an interior boundary. The continuity of velocity at the interface is automatically satisfied by using globally continuous finite element for the velocity in the fluid–structure mesh. The method is fast because we solve only a linear system at each time step. Three-dimensional numerical tests are presented.

Numerical simulation of parafoil inflation via a Robin–Neumann transmission-based approach

2017 ◽  
Vol 232 (4) ◽  
pp. 797-810 ◽  
Author(s):  
Shuai Nie ◽  
Yihua Cao ◽  
Zhenlong Wu
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Time Integration ◽  
Three Dimensional ◽  
Structural Deformation ◽  
Dimensional Case ◽  
Integration Scheme ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Highly Nonlinear

In this paper, a partitioned coupled iterative approach based on the Robin–Neumann transmission condition is proposed for the fluid–structure interaction simulation of the inflation process of a parafoil. The Reynold-averaged Navier–Stokes equations and the versatile finite element method are employed to solve the fluid flow field and the structural deformation, respectively. The generalized-α time integration scheme for the structure and the second order back Euler scheme for the fluid are incorporated in the Robin-Neumann method. A modified spring-transfinite interpolation hybrid method is exploited to detect the deformation of the grid and regenerate the grid for the fluid architecture. Both a two-dimensional case and a three-dimensional case are studied to examine the feasibility of the present approach. The simulation results reveal the evolution of the flow regime during the inflation process when the air pours into the parafoil. The whole inflation process can be concluded as two stages: the span-wise deployment and the longitudinal expansion. The numerical aerodynamic performance agrees well with that obtained by wind-tunnel experiment, suggesting the effectiveness of this method in handling such a highly nonlinear fluid–structure interaction in parachute inflation.

Fluid-Structure Interaction of Circular Cylinders With Elastic Surface

2011 ◽  
Author(s):  
Esmatullah Maiwand Sharify ◽  
Norio Arai ◽  
Shun Takahashi
Keyword(s):  
Stokes Equations ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Vibration Characteristics ◽  
Circular Cylinders ◽  
Elastic Surface ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Passive Deformation

This contribution presents the numerical study of Fluid Structure Interaction (FSI) problems and discusses the oscillatory characteristics of the elastic bodies and flowfield around circular cylinders. This paper deals with the motion of the elastic body and the flowfield using computational fluid dynamics (CFD) in two-dimensional and three-dimensional simulations. The governing equations are the continuity equation and incompressible Navier-Stokes equations. These equations are solved by MAC (Marker and cell) method by using Poisson equation for pressure component and momentum equations for velocity components. The convective terms of momentum equations are discretized by the third-order upwind Kawamura-Kuwahara scheme. All of the discretized equations are solved by the Successive over-relaxation (SOR) method. The equation of motion consists of mass-spring-damper system and it is solved by the 4th order Runge-Kutta method. The objective is to investigate the influence of the elastic surfaces with respect to the vibration characteristics of cylinders in unsteady flows. As a result, it is obtained that due to passive deformation of elastic surface for single cylinder the drag coefficient increases in both 2D and 3D cases. It is noticed that the effect of elastic surface in 2D case is stronger compared to 3D case. In the case of double cylinders, the elastic surface affects on vibration characteristics of upstream and downstream cylinders, and it is significant on downstream cylinder.

Extensive 3D analysis for fluid–structure interaction of spanwise flexible plunging wing 3D FSI Analysis for Spanwise Flexible Plunging Wing

2019 ◽  
Vol 123 (1262) ◽  
pp. 484-506
Author(s):  
H. Cho ◽  
N. Lee ◽  
S.-J. Shin ◽  
S. Lee
Keyword(s):  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Shell Element ◽  
Coupling Scheme ◽  
3D Analysis ◽  
Analysis Method ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Analysis

ABSTRACTIn this study, an improved fluid–structure interaction (FSI) analysis method is developed for a flapping wing. A co-rotational (CR) shell element is developed for its structural analysis. Further, a relevant non-linear dynamic formulation is developed based on the CR framework. Three-dimensional preconditioned Navier–Stokes equations are employed for its fluid analysis. An implicit coupling scheme is employed to combine the structural and fluid analyses. An explicit investigation of a 3D plunging wing is conducted using this FSI analysis method. A further investigation of this plunging wing is performed in relation to its operating condition. In addition, the relation between the wing’s aerodynamic performance and plunging motion is investigated.

Fluid Structure Interaction Homogenization for Tube Bundles: Significant Dissipative Effects

2018 ◽  
Author(s):  
Gianluca Artini ◽  
Daniel Broc
Keyword(s):  
Stokes Equations ◽  
Tube Bundle ◽  
Thermal Power ◽  
Fluid Structure Interaction ◽  
Coupled System ◽  
Nuclear Industry ◽  
Dynamical Analysis ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dissipative Effects

In the nuclear industry, tube arrays immersed in dense fluid are often encountered. These systems have a large amount of tubes necessary to increase the thermal power exchanged and their dynamical analysis for safety assessment and in life operation is one of the major concern of the nuclear industry. The presence of the fluid creates a strong coupling between tubes which must be taken into account for complete dynamical analysis. However, the description of fluid’s effects on oscillating structures demands great numerical efforts, especially when the tube number increases making any direct numerical simulations impossible to achieve. In this framework, homogenization methods are a possible solution in order to deal with tube bundle Fluid-Structure Interaction (FSI) problems; in fact, it gives the possibility to analyze the dynamics of the global coupled system in large domain with reasonable degree of detail and faster simulations times. At the CEA of Saclay a method based on the linearized Euler equations has been developed. It was presented in a previous PVP conference and its main goal is to assess the effect of spatial deformations of the tube bundle displacement field on the dynamic behavior. In the present paper, after an analysis on the modeling of fluid force where dissipative effects are significant, a homogenized model based on the Navier-Stokes equations is introduced. Simulations in bi-dimensional configurations for different excitations are performed.

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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