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108
Lattice Boltzmann method for 3D flows with curved boundary
 J. Comput. Phys
"... In this work, we investigate two issues that are important to computational efficiency and reliability in fluid dynamic applications of the lattice Boltzmann equation (LBE): (1) Computational stability and accuracy of different lattice Boltzmann models and (2) the treatment of the boundary condition ..."
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Cited by 53 (1 self)
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In this work, we investigate two issues that are important to computational efficiency and reliability in fluid dynamic applications of the lattice Boltzmann equation (LBE): (1) Computational stability and accuracy of different lattice Boltzmann models and (2) the treatment of the boundary conditions on curved solid boundaries and their 3D implementations. Three athermal 3D LBE models (Q15D3, Q19D3, and Q27D3) are studied and compared in terms of efficiency, accuracy, and robustness. The boundary treatment recently developed by Filippova and Hänel (1998, J. Comp.
Asymptotic analysis of the lattice Boltzmann equation
, 2005
"... In this article we analyze the lattice Boltzmann equation (LBE) by using the asymptotic expansion technique. We first relate the LBE to the finite discretevelocity model (FDVM) of the Boltzmann equation with the diffusive scaling. The analysis of this model directly leads to the incompressible Navi ..."
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Cited by 47 (5 self)
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In this article we analyze the lattice Boltzmann equation (LBE) by using the asymptotic expansion technique. We first relate the LBE to the finite discretevelocity model (FDVM) of the Boltzmann equation with the diffusive scaling. The analysis of this model directly leads to the incompressible Navier–Stokes equations, as opposed to the compressible Navier–Stokes equations obtained by the Chapman–Enskog analysis with convective scaling. We also apply the asymptotic analysis directly to the fully discrete LBE, as opposed to the usual practice of analyzing a continuous equation obtained through the Taylorexpansion of the LBE. This leads to a consistency analysis which provides orderbyorder information about the numerical solution of the LBE. The asymptotic technique enables us to analyze the structure of the leading order errors and the accuracy of numerically derived quantities, such as vorticity. It also justifies the use of RichardsonÕs extrapolation method. As an example, a twodimensional Taylorvortex flow is used to validate our analysis. The numerical results agree very well with our analytic predictions.
Lattice Boltzmann method for moving boundaries
, 2003
"... We propose a lattice Boltzmann method to treat moving boundary problems for solid objects moving in a fluid. The method is based on the simple bounceback boundary scheme and interpolations. The proposed method is tested in two flows past an impulsively started cylinder moving in a channel in two di ..."
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Cited by 36 (1 self)
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We propose a lattice Boltzmann method to treat moving boundary problems for solid objects moving in a fluid. The method is based on the simple bounceback boundary scheme and interpolations. The proposed method is tested in two flows past an impulsively started cylinder moving in a channel in two dimensions: (a) the flow past an impulsively started cylinder moving in a transient Couette flow; and (b) the flow past an impulsively started cylinder moving in a channel flow at rest. We obtain satisfactory results and also verify the Galilean invariance of the lattice Boltzmann method.
Lattice Boltzmann Model for Free Surface Flow for Modeling Foaming
 J. Stat. Phys
, 2005
"... We present a 2D and 3Dlattice Boltzmann model for the treatment of free surface flows including gas diffusion. Interface advection and related boundary conditions are based on the idea of the lattice Boltzmann equation. The fluid dynamic boundary conditions are approximated by using the mass and m ..."
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Cited by 19 (6 self)
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We present a 2D and 3Dlattice Boltzmann model for the treatment of free surface flows including gas diffusion. Interface advection and related boundary conditions are based on the idea of the lattice Boltzmann equation. The fluid dynamic boundary conditions are approximated by using the mass and momentum fluxes across the interface, which do not require explicit calculation of gradients. A similar procedure is applied to fulfill the diffusion boundary condition. Simple verification tests demonstrate the correctness of the algorithms. 2D and 3Dfoam evolution examples demonstrate the potential of the method.
Corrigendum to ”Lattice PoissonBoltzmann simulations of electroosmotic flows in microchannels
 J. Colloid Interface Sci. 296 (2006) 729736], J. Colloid Interface Sci
"... Abstract. This paper presents numerical analysis of electroosmotic flows (EOF) in charged anisotropic porousmedia using the lattice PoissonBoltzmannmethod (LPBM), which combines two sets of lattice evolution methods solving the nonlinear Poisson equation for electric potential distribution and the ..."
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Cited by 18 (6 self)
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Abstract. This paper presents numerical analysis of electroosmotic flows (EOF) in charged anisotropic porousmedia using the lattice PoissonBoltzmannmethod (LPBM), which combines two sets of lattice evolution methods solving the nonlinear Poisson equation for electric potential distribution and the NavierStokes equations for fluid flow respectively. Consistent boundary condition implementations are proposed for solving both the electrodynamics and the hydrodynamics on a same grid set. The anisotropic structure effects on EOF characteristics are therefore studied by modeling the electrically driven flows through ellipse arrays packed in a microchannel whose shape and orientation angle are used to control the anisotropy of porous media. The results show that flow rates increase with the axis length along the external electric field direction for a certain porosity and decrease with the angle between the semimajor axis and the bulk flow direction when the orientation angle is smaller than π/2. After introducing random factors into the microstructures of porous media, the statistical results of flow rate show that the anisotropy of microstructure decreases the permeability of EOFs in porous media.
Incompressible limits of lattice boltzmann equations using multiple relaxation times
 J. Comput. Phys
"... Lattice Boltzmann equations using multiple relaxation times are intended to be more stable than those using a single relaxation time. The additional relaxation times may be adjusted to suppress nonhydrodynamic modes that do not appear directly in the continuum equations, but may contribute to insta ..."
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Cited by 10 (3 self)
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Lattice Boltzmann equations using multiple relaxation times are intended to be more stable than those using a single relaxation time. The additional relaxation times may be adjusted to suppress nonhydrodynamic modes that do not appear directly in the continuum equations, but may contribute to instabilities on the grid scale. If these relaxation times are fixed in lattice units, as in previous work, solutions computed on a given lattice are found to diverge in the incompressible (small Mach number) limit. This nonexistence of an incompressible limit is analysed for an inclined one dimensional jet. An incompressible limit does exist if the nonhydrodynamic relaxation times are not fixed, but scaled by the Mach number in the same way as the hydrodynamic relaxation time that determines the viscosity. 1.
Concepts of waLBerla Prototype 0.1
 Chair for System Simulation, Univ. of Erlangen
, 2007
"... The waLBerla project was founded by the need for a persistent, general, fast, parallel lattice Boltzmann framework that is suitable for the simualtion of multiple computational fluid dynamic’s applications. In this technical report the improvements of the project for the Prototype 0.1 are presented. ..."
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Cited by 8 (6 self)
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The waLBerla project was founded by the need for a persistent, general, fast, parallel lattice Boltzmann framework that is suitable for the simualtion of multiple computational fluid dynamic’s applications. In this technical report the improvements of the project for the Prototype 0.1 are presented. These have been arbitrary boundary conditions, a generalized obstacle description, extension of the solver and the output modules for parallel usage, a validation of the project, incorporation of a physics engine for the management of obstacles and the introduction of patches, subdivisions of the fluid domain. It is shown that the with our local and parallel communication concept an efficient parallelization of the project has been accomplished. 1
Analysis of lattice Boltzmann initialization routines
, 2005
"... LB simulations can be affected by the arising of initial layers due to an inconsistent initialization of the discrete LB populations. We present some previously proposed initialization routines built to overcome that problem; using the asymptotic expansion technique, we show how their features can b ..."
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Cited by 7 (0 self)
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LB simulations can be affected by the arising of initial layers due to an inconsistent initialization of the discrete LB populations. We present some previously proposed initialization routines built to overcome that problem; using the asymptotic expansion technique, we show how their features can be analyzed and, in some cases, how accuracy and computational efficiency can be improved.
Evaluation of powerflow for aerodynamic applications
, 2002
"... A careful comparison of the performance of a commercially available LatticeBoltzmann Equation solver (PowerFLOW) was made with a conventional, blockstructured computational fluiddynamics code (CFL3D) for the flow over a twodimensional NACA0012 airfoil. The results suggest that the version of Po ..."
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Cited by 6 (0 self)
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A careful comparison of the performance of a commercially available LatticeBoltzmann Equation solver (PowerFLOW) was made with a conventional, blockstructured computational fluiddynamics code (CFL3D) for the flow over a twodimensional NACA0012 airfoil. The results suggest that the version of PowerFLOW used in the investigation produced solutions with large errors in the computed flow field; these errors are attributed to inadequate resolution of the boundary layer for reasons related to grid resolution and primitive turbulence modeling. The requirement of square grid cells in the PowerFLOW calculations limited the number of points that could be used to span the boundary layer on the wing and still keep the computation size small enough to fit on the available computers. Although not discussed in detail, disappointing results were also obtained with PowerFLOW for a cavity flow and for the flow around a generic helicopter configuration. KEY WORDS: PowerFLOW; lattice Boltzmann method; lattice gas automata; 2D flow past NACA0012 airfoil; aerodynamic simulations; turbulence modeling;