A Method for Analytical Solutions in the Lattice Boltzmann Method

Fuente: arXiv
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Main Authors: Larson, Jordan, Wagner, Alexander J.
Format: Preprint
Published: 2025
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author Larson, Jordan
Wagner, Alexander J.
author_facet Larson, Jordan
Wagner, Alexander J.
contents Analytical solutions to the lattice Boltzmann Equation make it possible to study the method itself, explore the properties of its collision operator, and identify implementations of boundary conditions. In this paper, we propose a method to find analytical solutions where the macroscopic flow profile is known. We test this method on bulk Couette flow aligned and inclined to the simulation lattice with the quadratic and entropic equilibrium distributions. Our method indeed provides an analytical solution to these flows when using the quadratic distribution. When the flow is aligned to the lattice, our method provides an analytical solution using the entropic distribution for practical relaxation times and shear rates. We show that a small even order truncation of the formal solution is optimal for accuracy-compute-time trade-off. In the inclined case, our method does not conserve momentum, by a small relative error, when using the entropic distribution. We also discover that entropic lattice Boltzmann method is not compatible with the angled Couette flow. We discuss the application of our method to more complicated flows.
format Preprint
id arxiv_https___arxiv_org_abs_2505_24170
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A Method for Analytical Solutions in the Lattice Boltzmann Method
Larson, Jordan
Wagner, Alexander J.
Fluid Dynamics
Computational Physics
Analytical solutions to the lattice Boltzmann Equation make it possible to study the method itself, explore the properties of its collision operator, and identify implementations of boundary conditions. In this paper, we propose a method to find analytical solutions where the macroscopic flow profile is known. We test this method on bulk Couette flow aligned and inclined to the simulation lattice with the quadratic and entropic equilibrium distributions. Our method indeed provides an analytical solution to these flows when using the quadratic distribution. When the flow is aligned to the lattice, our method provides an analytical solution using the entropic distribution for practical relaxation times and shear rates. We show that a small even order truncation of the formal solution is optimal for accuracy-compute-time trade-off. In the inclined case, our method does not conserve momentum, by a small relative error, when using the entropic distribution. We also discover that entropic lattice Boltzmann method is not compatible with the angled Couette flow. We discuss the application of our method to more complicated flows.
title A Method for Analytical Solutions in the Lattice Boltzmann Method
topic Fluid Dynamics
Computational Physics
url https://arxiv.org/abs/2505.24170