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.

Fluid-Structure Interaction for Hydrodynamic Problems: Impact Between a Tanker Bow Flare and a Submarine

2002 ◽  
Author(s):  
N. Aquelet ◽  
H. Lesourne ◽  
M. Souli
Keyword(s):  
Fluid Structure Interaction ◽  
Underwater Explosion ◽  
Slip Boundary Condition ◽  
Industrial Applications ◽  
Structural Deformation ◽  
Nuclear Submarine ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Slip Boundary ◽  
Eulerian Formulation

A methodology to predict the capacity of a nuclear submarine hull to act as a protective container and energy absorber under impact by an another underwater structure is needed. Principia Marine, company of Research in Shipbuilding (formerly IRCN, Institut de Recherche en Construction Navale), is responding to this need by developing an underwater impact crash prediction methodology based upon LS-DYNA3D software. Several physical phenomena with their own characteristic times follow one another at the time of the shock. So different but complementary tasks to develop this methodology were worked individually. This paper deals with contribution to this ongoing program that breaks up into two objectives. The first goal aims to highlight the effect of water on the structural deformation at the time of the collision between a nuclear submarine and a tanker ram bow, which is generally plane. The two-dimensional modelling of this collision uses an Eulerian formulation for the fluid and a Lagrangian formulation for the structure. The fluid-structure interaction is treated by an Euler/Lagrange penalty coupling. This method of coupling, which makes it possible to transmit the efforts in pressure of the Eulerian grid to the Lagrangian grid and conversely, is relatively a recent algorithmic development. It was successfully used in many scientific and industrial applications: the modelling of the attack of birds on the fuselage of a Jet for the Boeing Corporation, the underwater explosion shaking the oil platforms, and airbag simulation… The requirements of modelling for this algorithm are increasingly pointed. Thus, the second objective of this paper is to compare the results in pressures and velocities near the bulb for two cases, in the first one, the bulb is modelled by a slip boundary condition, in the second one, the bulb is a rigid Lagrangian structure, which involves the use of the Euler/Lagrange penalty coupling.

Numerical investigation of nonlinear fluid–structure interaction dynamic behaviors under a general Immersed Boundary-Lattice Boltzmann-Finite Element method

2018 ◽  
Vol 29 (04) ◽  
pp. 1850038 ◽  
Author(s):  
Chun-Lin Gong ◽  
Zhe Fang ◽  
Gang Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Lattice Boltzmann ◽  
Fluid Structure Interaction ◽  
Numerical Approach ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Flexible Objects ◽  
Element Method

A numerical approach based on the immersed boundary (IB), lattice Boltzmann and nonlinear finite element method (FEM) is proposed to simulate hydrodynamic interactions of very flexible objects. In the present simulation framework, the motion of fluid is obtained by solving the discrete lattice Boltzmann equations on Eulerian grid, the behaviors of flexible objects are calculated through nonlinear dynamic finite element method, and the interactive forces between them are implicitly obtained using velocity correction IB method which satisfies the no-slip conditions well at the boundary points. The efficiency and accuracy of the proposed Immersed Boundary-Lattice Boltzmann-Finite Element method is first validated by a fluid–structure interaction (F-SI) benchmark case, in which a flexible filament flaps behind a cylinder in channel flow, then the nonlinear vibration mechanism of the cylinder-filament system is investigated by altering the Reynolds number of flow and the material properties of filament. The interactions between two tandem and side-by-side identical objects in a uniform flow are also investigated, and the in-phase and out-of-phase flapping behaviors are captured by the proposed method.

Fluid–Structure Interaction Study and Flowrate Prediction Past a Flexible Membrane Using Immersed Boundary Method and Artificial Neural Network Techniques

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Mithun Kanchan ◽  
Ranjith Maniyeri
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Immersed Boundary Method ◽  
Fluid Structure Interaction ◽  
Immersed Boundary ◽  
Flexible Membrane ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Boundary Method ◽  
Artificial Neural

Abstract Many microfluidics-based applications involve fluid–structure interaction (FSI) of flexible membranes. Thin flexible membranes are now being widely used for mixing enhancement, particle segregation, flowrate control, drug delivery, etc. The FSI simulations related to these applications are challenging to numerically implement. In this direction, techniques like immersed boundary method (IBM) have been successful. In this study, two-dimensional numerical simulation of flexible membrane fixed at two end points in a rectangular channel subjected to uniform fluid flow is carried out at low Reynolds number using a finite volume based IBM. A staggered Cartesian grid system is used and SIMPLE algorithm is used to solve the governing continuity and Navier–Stokes equations. The developed model is validated using the previous research work and numerical simulations are carried out for different parametric test cases. Different membrane mode shapes are observed due to the complex interplay between the hydrodynamics and structural elastic forces. Since the membrane undergoes deformation with respect to inlet fluid conditions, a variation in flowrate past the flexible structure is confirmed. It is found that, by changing the membrane length, bending rigidity, and its initial position in the channel, flowrate can be controlled. Also, for membranes that are placed at the channel midplane undergoing self-excited oscillations, there exists a critical dimensionless membrane length condition L ≥ 1.0 that governs this behavior. Finally, an artificial neural network (ANN) model is developed that successfully predicts flowrate in the channel for different membrane parameters.

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