The complete numerical analysis of time splitting schemes which avoid strong coupling has rarely been addressed in the literature of unfitted mesh methods for incompressible fluid-structure interaction. In this paper,...
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The complete numerical analysis of time splitting schemes which avoid strong coupling has rarely been addressed in the literature of unfitted mesh methods for incompressible fluid-structure interaction. In this paper, an error analysis of the semi-implicit scheme recently reported in Fernandez and Gerosa (Int. J. Numer. Methods Eng. 122, 5384-5408, 2021) is performed for a linear fluid-structure interaction system. The analysis shows that, under a hyperbolic-CFL condition, the leading term in the energy error scales as O(h(r- 1/2)), where r = 1,2 stands for the extrapolation order of the solid velocity in the viscous fluid substep. The theoretical findings are illustrated via numerical experiments which show, in particular, that the considered method avoids the spatial non-uniformity issues of standard loosely coupled schemes and that it delivers practically the same accuracy as the strongly coupled scheme.
Extracorporeal membrane oxygenation (ECMO) is a vital mechanical circulatory support modality capable of restoring perfusion for the patient in circulatory failure. Despite increasing adoption of ECMO, there is incomp...
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Extracorporeal membrane oxygenation (ECMO) is a vital mechanical circulatory support modality capable of restoring perfusion for the patient in circulatory failure. Despite increasing adoption of ECMO, there is incomplete understanding of its effects on systemic hemodynamics and how the vasculature responds to varying levels of continuous retrograde perfusion. To gain further insight into the complex ECMO:failing heart circulation, computational fluid dynamics simulations focused on perfusion distribution and hemodynamic flow patterns were conducted using a patient-derived aorta geometry. Three case scenarios were simulated: (1) healthy control;(2) 90% ECMO-derived perfusion to model profound heart failure;and, (3) 50% ECMO-derived perfusion to model the recovering heart. fluid-structure interface simulations were performed to quantify systemic pressure and vascular deformation throughout the aorta over the cardiac cycle. ECMO support alters pressure distribution while decreasing shear stress. Insights derived from computational modeling may lead to better understanding of ECMO support and improved patient outcomes.
As a result of its wide range of applications, FSI has grabbed the attention of researchers and scientists. In this study we consider an incompressible, laminar fluid flowing through the bifurcated channel. The wavy w...
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As a result of its wide range of applications, FSI has grabbed the attention of researchers and scientists. In this study we consider an incompressible, laminar fluid flowing through the bifurcated channel. The wavy walls of the channel are considered elastic. Moreover, a magnetic field is applied towards the axial direction of the flow. Using a two-way fluid-structure interaction, an Arbitrary Lagrangian-Eulerian (ALE) formulation is used for coupling the problem. The problem is discretized using P 2 and P 1 finite element methods to approximate the displacement, pressure, and velocity. The linearized system of equations is solved using Newton's iterative scheme. The analysis is carried out for the Reynolds number and Hartman number. The ranges of the studied parameters are Reynolds number 300 & LE;R e & LE;1000 and Hartmann number 0 & LE;H a & LE;10 . The hemodynamic effects on the bifurcated channel and elastic walls are calculated using velocity, pressure, wall shear stresses (WSS), and loads at the walls. The study shows there is an increase in boundary load as the values of the Hartman number increase hence WSS increases. On the other hand, an increase in the Reynolds number increases the resistance forces hence velocity and WSS decrease. Also, numerical values of WSS for rigid and elastic walls are calculated. Studies showed that WSS decreases for the FSI case when compare to CFD (computational fluid dynamic) case.
In this paper, we study a nonlinear interaction problem between a thermoelastic shell and a heat-conducting fluid. The shell is governed by linear thermoelasticity equations and encompasses a time-dependent domain whi...
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In this paper, we study a nonlinear interaction problem between a thermoelastic shell and a heat-conducting fluid. The shell is governed by linear thermoelasticity equations and encompasses a time-dependent domain which is filled with a fluid governed by the full Navier-Stokes-Fourier system. The fluid and the shell are fully coupled, giving rise to a novel nonlinear moving boundary fluid-structure interaction problem involving heat exchange. The existence of a weak solution is obtained by combining three approximation techniques - decoupling, penalization and domain extension. In particular, the penalization and the domain extension allow us to use the methods already developed for compressible fluids on moving domains. In such a way, the proof is more elegant and the analysis is drastically simplified. Let us stress that this is the first time the heat exchange in the context of fluid-structure interaction problems is considered.
Pipe vibration induced by water hammer frequently emerges in water conveyance system, especially in the hydropower plant or pumped storage power station with long diversion pipelines. This vibration in turn affects th...
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Pipe vibration induced by water hammer frequently emerges in water conveyance system, especially in the hydropower plant or pumped storage power station with long diversion pipelines. This vibration in turn affects the hydraulic pulsation so that undesired fluid-structure interaction (FSI) arises. In this research, attention is given to a pipeline embedded in concrete. A six-equation model was derived to describe the fluid-pipe-concrete interaction considering Poisson coupling and junction coupling. With the elastic and homogeneous hypotheses, an iterative approach was proposed to solve this model, and the results were validated by experiment and classical water-hammer theory. Then dynamic FSI responses to water hammer were studied in a reservoir-pipe-valve physical system. Hydraulic pressure, pipe wall stress and axial motion were discussed with respect to different parameters of concrete. Results obtained by the two-equation model, four-equation model and six-equation model show characteristics of pressure wave and stress wave separately with and without FSI.
Under support forces from static pressure bearings, the solid deformations of static pressure spindle or slide systems will affect their performance, especially for those with high load-carrying capacity and stiffness...
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Under support forces from static pressure bearings, the solid deformations of static pressure spindle or slide systems will affect their performance, especially for those with high load-carrying capacity and stiffness. This paper proposes a steady modeling method to study the effect of fluid-structure interaction (FSI) on the thrust stiffness of an H-shaped aerostatic spindle. The proposed method can be readily applied to different static pressure spindles or slides, and can save a lot of time compared with the transient method, which is generally used to consider the phenomenon of FSI. The method proposed in this study is more suitable for studying the performance of spindles and slides with high load-carrying capacity and stiffness, especially in the design phase. In this paper, solid deformations, pressure distributions and the thrust stiffness are all obtained based on this method. Moreover, the effects of the axial position of the spindle and the air film thickness on the thrust stiffness are studied. The proposed method is verified by experimental results. The calculation error of the proposed method is reduced by nearly 77% compared with the traditional method ignoring FSI.
This paper presents a fluid-structure interaction (FSI) framework that combines an Arbitrary Lagrangian-Eulerian (ALE) formulation with skeleton-based structural models consisting of force-based frame elements. For th...
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This paper presents a fluid-structure interaction (FSI) framework that combines an Arbitrary Lagrangian-Eulerian (ALE) formulation with skeleton-based structural models consisting of force-based frame elements. For the first time in literature, a methodology is proposed to enable coupling between fluid and force-based frame elements through an ALE formulation. In the proposed methodology, communication between the fluid and skeleton-based domains is performed through a geometric model of the physical fluid- structure interface. With the use of force-based frame elements, the intent is to perform accurate FSI calculations in cases where axial, flexure, and shear motions dominate the structural responses. The proposed framework is evaluated against FSI problems involving steady and unsteady incompressible laminar flows and different structural models representing horizontal (beam) and vertical (column) solid members. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.
This study is concerned with the hydroelastic vibrations of sandwich micro-plates with functionally graded (FG) face sheets and metal core, interacting with sloshing liquid. For the purpose of the study, modified coup...
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This study is concerned with the hydroelastic vibrations of sandwich micro-plates with functionally graded (FG) face sheets and metal core, interacting with sloshing liquid. For the purpose of the study, modified couple stress theory with variable length-scale parameter is applied to catch the small-scale effects of the structure. The mechanical properties of FG sandwich micro-plate and length scale parameter are supposed to be variable through the thickness of the structure. The displacement field is formulated based on fifth-order shear deformation theory which considers transverse shear stresses and rotary inertias. The liquid is assumed to be ideal, and the continuity equation is utilized to obtain liquid velocity potential associated with bulging and sloshing modes. After deriving kinetic and potential energies related to the micro-plate and liquid, Rayleigh-Ritz approach is applied to obtain vibrational characteristics of the system. Some comparison studies are made to confirm the reliability and efficacy of the present work. Finally, in the discussion section, wet frequencies of the sandwich micro-plate are analyzed in graphs and tables for various parameters.
We present a method for computing fluid-structure interaction problems for multi body systems. The fluid flow equations are solved using a fractional-step method with the immersed boundary method proposed by Uhlmann (...
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We present a method for computing fluid-structure interaction problems for multi body systems. The fluid flow equations are solved using a fractional-step method with the immersed boundary method proposed by Uhlmann (2005). The equations of the rigid bodies are solved using recursive algorithms proposed by Felis (2017). The two systems of equations are weakly coupled, so that the resulting method is cost-effective. The accuracy of the method is demonstrated by comparison with two-and three-dimensional cases from the literature: the flapping of a flexible airfoil, the self propulsion of a plunging flexible plate, and the flapping of a flag in a free stream. As an illustration of the capabilities of the proposed method, two three-dimensional bioinspired applications are presented: an extension to three dimensions of the plunging flexible plate and a simple model of spider ballooning. (C) 2022 Elsevier Ltd. All rights reserved.
fluid-structure interaction(FSI)has a strong relation with layout of fluid delivery *** is liable to cause local ***,FSI analysis is necessary in many cases,especially for flexible pipe *** modeling consists of eight ...
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fluid-structure interaction(FSI)has a strong relation with layout of fluid delivery *** is liable to cause local ***,FSI analysis is necessary in many cases,especially for flexible pipe *** modeling consists of eight governing equations and then completely solved via the finite volume method(FVM).Friction,Poisson and joint couplings were discussed in detail to reveal the influence of a Z-shaped pipe with different supports and elbows on *** the feasibility of solving FSI by FVM was verified,the different effects of free,fixed and elastic supports on FSI in the commonly used and simplified Z-shaped pipe were further *** indicated that different support stiffness lead to various FSI *** coupling occurs at the elbow and less support is considered,then the pipe has a relatively large amplitude and complex pressure fluctuation.
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