Efficiency of Diffuse and Sharp Interface Strongly Coupled Fluid Structure Interaction Methods in Fixed and Moving Boundaries

2016 ◽  
Author(s):  
Fazlolah Mohaghegh ◽  
H. S. Udaykumar
Keyword(s):  
Fluid Structure Interaction ◽  
Mass Effect ◽  
Sharp Interface ◽  
Diffuse Interface ◽  
Immersed Boundary ◽  
Immersed Boundary Methods ◽  
Time Step ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction

Efficiency of different types of immersed boundary methods in the fluid structure interaction (FSI) analysis is studied for different cases. Two different formulations of smoothed profile method (SPM) [1, 2] as diffuse interface approaches are compared with the ghost fluid method (GFM) [3, 4] as sharp interface method (SIM) [5]. First, the original SPM which has two pressure Poisson equations (SPM2P) is modified to a novel formulation for SPM with only one pressure Poisson equation (SPM1P) and then validated. The efficiency study is performed for SPM1P, SPM2P and SIM. The results show that when the solid object is fixed, the explicit solution of SIM is faster than the two SPMs. However, when the solid is moving and strongly coupled formulations is used, SPM1P will be the fastest method. It is shown that the efficiency of the strongly coupled formulations depends on the number of subiterations required in each time step to reach the converged implicit solution. SPM1P and SPM2P need less number of subiterations in comparison with SIM and they are faster. When the added mass effect is high, the efficiency of SPM becomes more noticeable as the required number of subiterations is significantly less in SPM. Finally, SPM1P is faster than SPM2P in all cases however, the accuracy of SPM2P in predicting the flow pattern is better than SPM1P.

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.

An Immersed Boundary Proper Generalized Decomposition (IB-PGD) for Fluid–Structure Interaction Problems

2018 ◽  
Vol 15 (06) ◽  
pp. 1850045
Author(s):  
C. Le-Quoc ◽  
Linh A. Le ◽  
V. Ho-Huu ◽  
P. D. Huynh ◽  
T. Nguyen-Thoi
Keyword(s):  
Fluid Flow ◽  
Stokes Equations ◽  
Complex Geometry ◽  
Fluid Structure Interaction ◽  
Fluid Pressure ◽  
Immersed Boundary ◽  
Proper Generalized Decomposition ◽  
Time Step ◽  
Fluid Structure ◽  
Structure Interaction

Proper generalized decomposition (PGD), a method looking for solutions in separated forms, was proposed recently for solving highly multidimensional problems. In the PGD, the unknown fields are constructed using separated representations, so that the computational complexity scales linearly with the dimension of the model space instead of exponential scaling as in standard grid-based methods. The PGD was proven to be effective, reliable and robust for some simple benchmark fluid–structure interaction (FSI) problems. However, it is very hard or even impossible for the PGD to find the solution of problems having complex boundary shapes (i.e., problems of fluid flow with arbitrary complex geometry obstacles). The paper hence further extends the PGD to solve FSI problems with arbitrary boundaries by combining the PGD with the immersed boundary method (IBM) to give a so-called immersed boundary proper generalized decomposition (IB-PGD). In the IB-PGD, a forcing term constructed by the IBM is introduced to Navier–Stokes equations to handle the influence of the boundaries and the fluid flow. The IB-PGD is then applied to solve Poisson’s equation to find the fluid pressure distribution for each time step. The numerical results for three problems are presented and compared to those of previous publications to illustrate the robustness and effectiveness of the IB-PGD in solving complex FSI problems.

Fast and Accurate Simulation of Strongly Coupled Fluid-Structure Interaction Using a Direct Forcing Immersed Boundary Method

2011 ◽  
Author(s):  
Jianming Yang ◽  
Frederick Stern
Keyword(s):  
Immersed Boundary Method ◽  
Fluid Structure Interaction ◽  
Immersed Boundary ◽  
Coupling Scheme ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction ◽  
Boundary Method ◽  
Embedded Boundary ◽  
Direct Forcing

In this paper, a direct forcing immersed boundary method is presented for the simple and efficient simulation of strongly coupled fluid-structure interaction. The previous formulation by Yang and Balaras (An embedded-boundary formulation for large-eddy simulation of turbulent flows interacting with moving boundaries, J. Comput. Phys. 215 (2006) 12–40) is greatly simplified without sacrificing the overall accuracy. The fluid-structure coupling scheme of Yang et al. (A strongly-coupled, embedded-boundary method for fluid-structure interactions of elastically mounted rigid bodies, J. Fluids Struct. 24 (2008) 167–182) is also significantly expedited without altering the strong coupling property. Several cases are examined and compared with the results from the previous formulations to demonstrate the accuracy, simplicity and efficiency of the new method.

scholarly journals On the Choice of Interface Parameters in Robin–Robin Loosely Coupled Schemes for Fluid–Structure Interaction

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 213
Author(s):  
Giacomo Gigante ◽  
Christian Vergara
Keyword(s):  
Fluid Structure Interaction ◽  
Time Discretization ◽  
Mass Effect ◽  
Reduction Factor ◽  
Cylindrical Domain ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction ◽  
Loosely Coupled ◽  
Interface Parameters

We consider two loosely coupled schemes for the solution of the fluid–structure interaction problem in the presence of large added mass effect. In particular, we introduce the Robin–Robin and Robin–Neumann explicit schemes where suitable interface conditions of Robin type are used. For the estimate of interface Robin parameters which guarantee stability of the numerical solution, we propose a new strategy based on the optimization of the reduction factor of the corresponding strongly coupled (implicit) scheme, by means of the optimized Schwarz method. To check the suitability of our proposals, we show numerical results both in an ideal cylindrical domain and in a real human carotid. Our results showed the effectiveness of our proposal for the calibration of interface parameters, which leads to stable results and shows how the explicit solution tends to the implicit one for decreasing values of the time discretization parameter.

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