Fluid–Structure Interaction of High Aspect-Ratio Hair-Like Micro-Structures Through Dimensional Transformation Using Lattice Boltzmann Method

2016 ◽  
Vol 08 (08) ◽  
pp. 1650095 ◽  
Author(s):  
H. Devaraj ◽  
Kean C. Aw ◽  
E. Haemmerle ◽  
R. Sharma
Keyword(s):  
Fluid Flow ◽  
Drag Force ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Momentum Exchange ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Micro Structures

3D printed hair-like micro-structures have been previously demonstrated in a novel micro-fluidic flow sensor aimed at sensing air flows down to rates of a few milliliters per second. However, there is a lack of in-depth understanding of the structural response of these ‘micro-hairs' under a fluid flow field. This paper demonstrates the use of lattice Boltzmann methods (LBM) to understand this structural response towards a better optimization of the micro-hair flow sensors designed to suit the end applications' needs. The LBM approach was chosen as an efficient alternative to simulate Navier–Stokes equations for modeling fluid flow around complex geometries primarily for improved accuracy and simplicity with lesser computational costs. As the spatial dimensions of the sensor's flow channel are much larger in comparison to the actual micro-hairs (the sensing element), a multidimensional approach of combining two-dimensional (D2Q9) and three-dimensional (D3Q19) lattice configurations were implemented for improved computational speeds and efficiency. The drag force on the micro-hairs was estimated using the momentum-exchange method in the D3Q19 configuration and this drag force is transferred to the structural analysis model which determines the micro-hair deformation using Euler–Bernoulli beam theory. The entirety of the LBM Fluid–Structure Interaction (FSI) model was implemented within MATLAB and the obtained results are compared against the numerical model implemented on a commercially available software package.

Fluid-Structure Interaction Approach for Numerical Investigation of a Flexible Hydrofoil Deformations in Turbulent Fluid Flow

2018 ◽  
Author(s):  
M. Benaouicha ◽  
S. Guillou ◽  
A. Santa Cruz ◽  
H. Trigui
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Time Step ◽  
Fluid Structure ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Structure Interaction ◽  
Ale Formulation

The study deals with a 3D Fluid-Structure Interaction (FSI) numerical model of a rectangular cantilevered flexible hydrofoil subjected to a turbulent fluid flow regime. The structural response and dynamic deformations are studied by analyzing the oscillations frequencies and amplitudes, under a hydrodynamics loads. The obtained numerical results are confronted with experimental ones, for validation. The numerical model is performed in the same geometric, physical and material conditions as the experimental set-up carried out in a hydrodynamic tunnel. A polyacetal (POM) flexible hydrofoil NACA0015 with an angle of attack of 8° is considered to be immersed in a fluid flow at a Reynold number of 3 × 105. The structure is initially at rest and then moved by the action of the fluid flow. The numerical model is based on a strong coupling procedure for solving the Fluid-Structure Interaction problem. The Arbitrary Lagrangian-Eulerian (ALE) formulation of the Navier-Stokes equations is used and an anisotropic diffusion equation is solved to compute the fluid mesh velocity and position at each time step. The finite volume method is used for the numerical resolution of the fluid dynamics equations. The structure deformations are described by the linear elasticity equation which is solved by the finite elements method. The Fluid-Structure coupled problem is solved by using the partitioned FSI implicit algorithm. A good agreement between numerical and experimental results for the hydrodynamics coefficients and hydrofoil deformations, maximum deflection and frequencies is obtained. The added mass and damping are analyzed and then the FSI effect on the dynamic deformations of the structure is highlighted.

Wake Interaction Using Lattice Boltzmann Method

2018 ◽  
pp. 223-261
Author(s):  
K. Karthik Selva Kumar ◽  
L. A. Kumaraswamidhas
Keyword(s):  
Fluid Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Computational Simulation ◽  
Fluid Structure Interaction ◽  
Flow Characteristics ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fluid Flow Characteristics ◽  
Boltzmann Method

In this chapter, a brief discussion about the application of lattice Boltzmann method on complex flow characteristics over circular structures is presented. A two-dimensional computational simulation is performed to study the fluid flow characteristics by employing the lattice Boltzmann method (LBM) with respect to Bhatnagar-Gross-Krook (BGK) collision model to simulate the interaction of fluid flow over the circular cylinders at different spacing conditions. From the results, it is observed that there is no significant interaction between the wakes for the transverse spacing's ratio higher than six times the cylinder diameter. For smaller transverse spacing ratios, the fluid flow regimes were recognized with presence of vortices. Apart from that, the drag coefficient signals are revealed as chaotic, quasi-periodic, and synchronized regimes, which were observed from the results of vortex shedding frequencies and fluid structure interaction frequencies. The strength of the latter frequency depends on spacing between the cylinders; in addition, the frequency observed from the fluid structure interaction is also associated with respect to the change in narrow and wide wakes behind the surface of the cylinder. Further, the St and mean Cd are observed to be increasing with respect to decrease in the transverse spacing ratio.

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.

Development of Weighted Residual Based Lattice Boltzmann Techniques for Fluid-Structure Interaction Application

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Y. W. Kwon ◽  
Jong Chull Jo
Keyword(s):  
Fluid Flow ◽  
Lattice Boltzmann ◽  
Fluid Structure Interaction ◽  
Computational Techniques ◽  
Time Step ◽  
Fluid Structure ◽  
Shell Elements ◽  
Lattice Boltzmann Methods ◽  
Structure Interaction ◽  
Domain Structures

New computational techniques were developed for the analysis of fluid-structure interaction. The fluid flow was solved using the newly developed lattice Boltzmann methods, which could solve irregular shape of fluid domains for fluid-structure interaction. To this end, the weighted residual based lattice Boltzmann methods were developed. In particular, both finite element based and element-free based lattice Boltzmann techniques were developed for the fluid domain. Structures were analyzed using either beam or shell elements depending on the nature of the structures. Then, coupled transient fluid flow and structural dynamics were solved one after another for each time step. Numerical examples for both 2D and 3D fluid-structure interaction problems, as well as fluid flow only problems, were presented to demonstrate the developed techniques.

Coupled Finite Element Based Lattice Boltzmann Equation and Structural Finite Elements for Fluid-Structure Interaction Application

2008 ◽  
Author(s):  
Y. W. Kwon ◽  
J. C. Jo
Keyword(s):  
Finite Element ◽  
Fluid Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Fluid Structure Interaction ◽  
Computational Technique ◽  
Time Step ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Boltzmann Method

A computational technique was developed for analysis of fluid-structure interaction. The fluid flow was solved using the lattice Boltzmann method which found to be computationally simple and efficient. In order to apply the lattice Boltzmann method to irregular shapes of fluid domains, the finite element based lattice Boltzmann method was developed. In addition, the turbulent model was also implemented into the lattice Boltzmann formulation. Structures were analyzed using either beam or shell elements depending of the nature of the structures. Then, coupled transient fluid flow and structural dynamics were solved one after another for each time step. Numerical examples for both 2-D and 3-D fluid-structure interaction problems were presented to demonstrate the developed techniques.

The hydrodynamic FORCE of fluid–structure interaction interface in lattice Boltzmann simulations

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040085
Author(s):  
Ying Tong ◽  
Jian Xia
Keyword(s):  
Relaxation Time ◽  
Lattice Boltzmann ◽  
Numerical Solutions ◽  
Hydrodynamic Force ◽  
Critical Role ◽  
Fluid Structure Interaction ◽  
Momentum Exchange ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Lattice Resolution

The hydrodynamic force (HF) evaluation plays a critical role in the numerical simulation of fluid–structure interaction (FSI). By directly using the distribution functions of lattice Boltzmann equation (LBE) to evaluate the HF, the momentum exchange algorithm (MEA) has excellent features. Particularly, it is independent of boundary geometry and avoids integration on the complex boundary. In this work, the HF of lattice Boltzmann simulation (LBS) is evaluated by using the MEA. We conduct a comparative study to evaluate two lattice Boltzmann models for constructing the flow solvers, including the LBE with single-relaxation-time (SRT) and multiple-relaxation-time (MRT) collision operators. The second-order boundary condition schemes are used to address the curve boundary. The test case of flow past a cylinder asymmetrically placed in a channel is simulated. Comparing the numerical solutions of Lattice Boltzmann method (LBM) with those of Navier–Stokes equations in the literature, the influence of collision relaxation model, boundary conditions and lattice resolution is investigated. The results demonstrate that the MRT-LB improves the numerical stability of the LBM and the accuracy of HF.

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.

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