scholarly journals Simulation of Fluid-Structure and Fluid-Mediated Structure-Structure Interactions in Stokes Regime Using Immersed Boundary Method

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Masoud Baghalnezhad ◽  
Abdolrahman Dadvand ◽  
Iraj Mirzaee
Keyword(s):  
Equilibrium State ◽  
Stokes Flow ◽  
Immersed Boundary Method ◽  
Deformable Body ◽  
Fluid Motion ◽  
Immersed Boundary ◽  
Immersed Interface Method ◽  
Computational Point ◽  
Fluid Structure ◽  
Boundary Method

The Stokes flow induced by the motion of an elastic massless filament immersed in a two-dimensional fluid is studied. Initially, the filament is deviated from its equilibrium state and the fluid is at rest. The filament will induce fluid motion while returning to its equilibrium state. Two different test cases are examined. In both cases, the motion of a fixed-end massless filament induces the fluid motion inside a square domain. However, in the second test case, a deformable circular string is placed in the square domain and its interaction with the Stokes flow induced by the filament motion is studied. The interaction between the fluid and deformable body/bodies can become very complicated from the computational point of view. An immersed boundary method is used in the present study. In order to substantiate the accuracy of the numerical method employed, the simulated results associated with the Stokes flow induced by the motion of an extending star string are compared well with those obtained by the immersed interface method. The results show the ability and accuracy of the IBM method in solving the complicated fluid-structure and fluid-mediated structure-structure interaction problems happening in a wide variety of engineering and biological systems.

FINITE ELEMENT APPROACH TO IMMERSED BOUNDARY METHOD WITH DIFFERENT FLUID AND SOLID DENSITIES

2011 ◽  
Vol 21 (12) ◽  
pp. 2523-2550 ◽  
Author(s):  
DANIELE BOFFI ◽  
NICOLA CAVALLINI ◽  
LUCIA GASTALDI
Keyword(s):  
Finite Element ◽  
Immersed Boundary Method ◽  
Stokes Equations ◽  
Numerical Procedure ◽  
Biological Tissues ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Finite Element Approach ◽  
Boundary Method ◽  
Element Approach

The Immersed Boundary Method (IBM) has been designed by Peskin for the modeling and the numerical approximation of fluid-structure interaction problems, where flexible structures are immersed in a fluid. In this approach, the Navier–Stokes equations are considered everywhere and the presence of the structure is taken into account by means of a source term which depends on the unknown position of the structure. These equations are coupled with the condition that the structure moves at the same velocity of the underlying fluid. Recently, a finite element version of the IBM has been developed, which offers interesting features for both the analysis of the problem under consideration and the robustness and flexibility of the numerical scheme. Initially, we considered structure and fluid with the same density, as it often happens when dealing with biological tissues. Here we study the case of a structure which can have a density higher than that of the fluid. The higher density of the structure is taken into account as an excess of Lagrangian mass located along the structure, and can be dealt with in a variational way in the finite element approach. The numerical procedure to compute the solution is based on a semi-implicit scheme. In fluid-structure simulations, nonimplicit schemes often produce instabilities when the density of the structure is close to that of the fluid. This is not the case for the IBM approach. In fact, we show that the scheme enjoys the same stability properties as in the case of equal densities.

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.

Computation of Turbulent Flows in Complex and Moving Geometries Using Immersed Boundary Method

2003 ◽  
Author(s):  
Mayank Tyagi ◽  
Sumanta Acharya
Keyword(s):  
Turbulent Flows ◽  
Immersed Boundary Method ◽  
Complex Geometry ◽  
Fluid Motion ◽  
The Body ◽  
Immersed Boundary ◽  
Full Potential ◽  
Heated Cylinder ◽  
Boundary Method ◽  
Trapped Vortex

A solution methodology for complex turbulent flows of industrial interests is developed using Immersed Boundary Method (IBM). IBM combines the efficiency inherent in using a fixed Cartesian grid to compute the fluid motion, along with the ease of tracking the immersed boundary at a set of moving Lagrangian points. IBM relies upon the body force terms added in the momentum equations to represents the complex geometry on a fixed Cartesian mesh. Resolution issues for turbulent flows can be addressed by Large Eddy Simulation (LES) technique provided an accurate and robust Subgrid Stress (SGS) model is available. Higher order of numerical accuracy schemes for turbulent flows can be maintained as well as the geometrical complexities can be rendered physically by combining LES with IBM. The proposed methodology is simple and ideally suited for the moving geometries involving no-slip walls with prescribed trajectories and locations. IBM is validated for the laminar flow past a heated cylinder in a channel and LES is validated for the turbulent lid-driven cavity flow. LES-IBM is then is used to render complex geometry of trapped vortex combustor to study fluid mixing inside trapped vortex cavity. To demonstrate the full potential of LES-IBM, a complex moving geometry problem of stator-rotor interaction is solved.

Study of Fluid Structure Interaction Using Sharp Interface Immersed Boundary Method

2016 ◽  
Author(s):  
Long He ◽  
Keyur Joshi ◽  
Danesh Tafti
Keyword(s):  
Immersed Boundary Method ◽  
Fluid Structure Interaction ◽  
Linear Structure ◽  
Current Approach ◽  
Sharp Interface ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Boundary Method ◽  
Coupling Algorithms

In this work, we present an approach for solving fluid structure interaction problems by combining a non-linear structure solver with an incompressible fluid solver using immersed boundary method. The implementation of the sharp-interface immersed boundary method with the fluid solver is described. A structure solver with the ability to handle geometric nonlinearly is developed and tested with benchmark cases. The partitioned fluid-structure coupling algorithm with the strategy of enforcing boundary conditions at the fluid/structure interaction is given in detail. The fully coupled FSI approach is tested with the Turek and Hron fluid-structure interaction benchmark case. Both strong coupling and weak coupling algorithms are examined. Predictions from the current approach show good agreement with the results reported by other researchers.

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