Application of the Lattice Boltzmann Method for Fluid Flow around Complex Geometry

2014 ◽  
Vol 554 ◽  
pp. 230-235
Author(s):  
Leila Jahanshaloo ◽  
Nor Azwadi Che Sidik ◽  
Emad Kermani
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Complex Geometry ◽  
Drag Forces ◽  
Lattice Boltzmann Simulations ◽  
Lattice Arrangement ◽  
Boundary Treatments ◽  
Lift And Drag ◽  
Boltzmann Method ◽  
Fluid Interaction

In recent years, several strategies have been proposed to deal with complex geometry to study particle-fluid interaction using lattice Boltzmann method. Curved boundary treatments have been suggested to improve the accuracy of the stair-shaped approximation in conventional lattice Boltzmann simulations. This paper presents numerical analysis of three interpolation methods for confined flow around blockage positioned inside a channel. A two-dimensional nine velocity lattice arrangement was chosen to discretize the fluid domain and single relaxation time technique is applied in this study. The results are presented in terms of velocity contour, lift and drag forces variation for three different shapes of blockage. The simulations results are then compared with those obtained using the three different interpolating treatments. Some of these methods show more adaptability for force evaluating on distinct surfaces.

Rayleigh-Taylor Instability Studied With Multi-Relaxation Lattice Boltzmann Method

2013 ◽  
Author(s):  
Saeed J. Almalowi ◽  
Dennis E. Oztekin ◽  
Alparslan Oztekin
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Early Stage ◽  
Density Ratio ◽  
Side Wall ◽  
Immiscible Fluids ◽  
Distribution Functions ◽  
Lattice Arrangement ◽  
Boltzmann Method ◽  
Late Stages

Multi relaxation lattice Boltzmann method is implemented to study Rayleigh-Taylor instabilities. Two immiscible fluids (oil and water) are arrayed into three layers. D2Q9 lattice arrangement for two dimensional computational domains is employed. Density distribution functions for each fluid and distribution functions for the coloring step are determined. The evolution of the interface is identified with the coloring step. Buoyancy and other interaction forces, created by buoyancy, between phases are modeled. Two cases are studied one with periodic boundary condition instead of a side wall, and one bounded on all sides. The study is done with an aspect ratio of two and a density ratio of 1.2. The early and late stages of the instability are characterized. The early stage of both cases shows the initial periodic disturbance being amplified rapidly on the lower interface. The late stages show mushroom-like structures, with significant distortions occurring on the bounded case.

Modeling groundwater flow by lattice Boltzmann method in curvilinear coordinates

2015 ◽  
Vol 26 (02) ◽  
pp. 1550013 ◽  
Author(s):  
Ljubomir Budinski ◽  
Julius Fabian ◽  
Matija Stipic
Keyword(s):  
Groundwater Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Complex Geometry ◽  
Poisson’S Equation ◽  
Curvilinear Coordinates ◽  
Computational Domain ◽  
Poisson's Equation ◽  
Equilibrium Function ◽  
Boltzmann Method

In order to promote the use of the lattice Boltzmann method (LBM) for the simulation of isotropic groundwater flow in a confined aquifer with arbitrary geometry, Poisson's equation was transformed into a curvilinear coordinate system. With the metric function between the physical and the computational domain established, Poisson's equation written in Cartesian coordinates was transformed in curvilinear coordinates. Following, the appropriate equilibrium function for the D2Q9 square lattice has been defined. The resulting curvilinear formulation of the LBM for groundwater flow is capable of modeling flow in domains of complex geometry with the opportunity of local refining/coarsening of the computational mesh corresponding to the complexity of the flow pattern and the required accuracy. Since the proposed form of the LBM uses the transformed equation of flow implemented in the equilibrium function, finding a solution does not require supplementary procedures along the curvilinear boundaries, nor in the zones requiring mesh density adjustments. Thus, the basic concept of the LBM is completely maintained. The improvement of the proposed LBM over the previously published classical methods is completely verified by three examples with analytical solutions. The results demonstrate the advantages of the proposed curvilinear LBM in modeling groundwater flow in complex flow domains.

LATTICE BOLTZMANN SIMULATIONS OF DROP DEFORMATION AND BREAKUP IN SHEAR FLOWS

2003 ◽  
Vol 17 (01n02) ◽  
pp. 21-26 ◽  
Author(s):  
T. INAMURO ◽  
R. TOMITA ◽  
F. OGINO
Keyword(s):  
Reynolds Number ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Shear Flows ◽  
Immiscible Fluids ◽  
Drop Deformation ◽  
Lattice Boltzmann Simulations ◽  
Boltzmann Method

A lattice Boltzmann method for multicomponent immiscible fluids is applied to simulations of drop deformation and breakup in shear flows for various capillary numbers and viscosity ratios at three different Revnolds numbers, Re = 0.2, 1, 10. The effect of the Reynolds number on drop deformation and breakup in shear flows is investigated. It is found that the drop is easier to deform and to be ruptured as the Reynolds number increases.

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