HYBRID LATTICE BOLTZMANN AND FINITE VOLUME METHODS FOR FLUID FLOW PROBLEMS

2014 ◽  
Vol 12 (3) ◽  
pp. 177-192 ◽  
Author(s):  
Zheng Li ◽  
Mo Yang ◽  
Yuwen Zhang
Keyword(s):  
Fluid Flow ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Finite Volume Methods ◽  
Flow Problems

Effect of Slit Inclusions in Drag Reduction of Flow over Cylinders

2016 ◽  
Vol 846 ◽  
pp. 18-22
Author(s):  
Rohit Bhattacharya ◽  
Abouzar Moshfegh ◽  
Ahmad Jabbarzadeh
Keyword(s):  
Fluid Flow ◽  
Drag Reduction ◽  
Drag Coefficient ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Circular Cross Section ◽  
Finite Volume Methods ◽  
Turbulent Regime ◽  
Ansys Fluent ◽  
Comparison Of The Results

The flow over bluff bodies is separated compared to the flow over streamlined bodies. The investigation of the fluid flow over a cylinder with a streamwise slit has received little attention in the past, however there is some experimental evidence that show for turbulent regime it reduces the drag coefficient. This work helps in understanding the fluid flow over such cylinders in the laminar regime. As the width of the slit increases the drag coefficient keeps on reducing resulting in a narrower wake as compared to what is expected for flow over a cylinder. In this work we have used two different approaches in modelling a 2D flow for Re=10 to compare the results for CFD using finite volume method (ANSYS FLUENTTM) and Lattice Boltzmann methods. In all cases cylinders of circular cross section have been considered while slit width changing from 10% to 40% of the cylinder diameter. . It will be shown that drag coefficient decreases as the slit ratio increases. The effect of slit size on drag reduction is studied and discussed in detail in the paper. We have also made comparison of the results obtained from Lattice Boltzmann and finite volume methods.

Time-Accurate Flow Simulations Using a Finite-Volume Based Lattice Boltzmann Flow Solver with Dual Time Stepping Scheme

2016 ◽  
Vol 13 (06) ◽  
pp. 1650035 ◽  
Author(s):  
Goktan Guzel ◽  
Ilteris Koc
Keyword(s):  
Fluid Flow ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Computational Effort ◽  
Flow Solver ◽  
Flow Problems ◽  
Time Stepping ◽  
Dual Time Stepping ◽  
Difference Formula ◽  
Finite Volume Approach

In this study, the Lattice Boltzmann Method (LBM) is implemented through a finite-volume approach to perform 2D, incompressible, and time-accurate fluid flow analyses on structured grids. Compared to the standard LBM (the so-called stream and collide scheme), the finite-volume approach followed in this study necessitates more computational effort, but the major limitations of the former on grid uniformity and Courant–Friedrichs–Lewy (CFL) number that is to be one are removed. Even though these improvements pave the way for the possibility of solving more practical fluid flow problems with the LBM, time-accurate simulations are still restricted due to the stability criteria dictated by high-aspect ratio grid cells that are usually required for adequate resolution of boundary layers and the stiffness due to the nature of the equation that are being solved. To overcome this limitation, a Dual Time Stepping (DTS) scheme, which iterates the solution in pseudo time using an Implicit-Explicit (IMEX) Runge–Kutta method while advancing the solution in physical time with an explicit scheme (backward difference formula), is developed and implemented. The accuracy of the resulting flow solver is evaluated using benchmark flow problems and overall second-order accuracy is demonstrated.

Simulation of Turbulent Flows Using a Finite-Volume Based Lattice Boltzmann Flow Solver

2014 ◽  
Vol 17 (1) ◽  
pp. 213-232 ◽  
Author(s):  
Goktan Guzel ◽  
Ilteris Koc
Keyword(s):  
Fluid Flow ◽  
Turbulent Flows ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Computational Effort ◽  
Computational Domain ◽  
Flow Solver ◽  
Turbulent Fluid Flow ◽  
Finite Volume Approach ◽  
Volume Method

AbstractIn this study, the Lattice Boltzmann Method (LBM) is implemented through a finite-volume approach to perform 2-D, incompressible, and turbulent fluid flow analyses on structured grids. Even though the approach followed in this study necessitates more computational effort compared to the standard LBM (the so called stream and collide scheme), using the finite-volume method, the known limitations of the stream and collide scheme on lattice to be uniform and Courant-Friedrichs-Lewy (CFL) number to be one are removed. Moreover, the curved boundaries in the computational domain are handled more accurately with less effort. These improvements pave the way for the possibility of solving fluid flow problems with the LBM using coarser grids that are refined only where it is necessary and the boundary layers might be resolved better.

Extension of lattice Boltzmann flux solver for simulation of compressible multi-component flows

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840001 ◽  
Author(s):  
Li-Ming Yang ◽  
Chang Shu ◽  
Wen-Ming Yang ◽  
Yan Wang
Keyword(s):  
Fluid Flow ◽  
Euler Equations ◽  
Lattice Boltzmann ◽  
Passive Scalar ◽  
Two Phase ◽  
Material Interfaces ◽  
Flow Problems ◽  
Numerical Fluxes ◽  
Model Equations ◽  
Interface Equations

The lattice Boltzmann flux solver (LBFS), which was presented by Shu and his coworkers for solving compressible fluid flow problems, is extended to simulate compressible multi-component flows in this work. To solve the two-phase gas–liquid problems, the model equations with stiffened gas equation of state are adopted. In this model, two additional non-conservative equations are introduced to represent the material interfaces, apart from the classical Euler equations. We first convert the interface equations into the full conservative form by applying the mass equation. After that, we calculate the numerical fluxes of the classical Euler equations by the existing LBFS and the numerical fluxes of the interface equations by the passive scalar approach. Once all the numerical fluxes at the cell interface are obtained, the conservative variables at cell centers can be updated by marching the equations in time and the material interfaces can be identified via the distributions of the additional variables. The numerical accuracy and stability of present scheme are validated by its application to several compressible multi-component fluid flow problems.

High-order finite volume methods for viscoelastic flow problems

2004 ◽  
Vol 199 (1) ◽  
pp. 16-40 ◽  
Author(s):  
M. Aboubacar ◽  
T.N. Phillips ◽  
H.R. Tamaddon-Jahromi ◽  
B.A. Snigerev ◽  
M.F. Webster
Keyword(s):  
Finite Volume ◽  
Finite Volume Methods ◽  
High Order ◽  
Viscoelastic Flow ◽  
Flow Problems
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