# Gaussian Lattice Boltzmann method and its applications to rarefied flows

## TL;DR

This paper introduces a new discretization method for the BGK kinetic equation using Gaussian lattice Boltzmann models, improving accuracy and stability in simulating rarefied flows across various flow problems.

## Contribution

A novel hierarchy of LB models for the BGK equation is developed, enhancing precision and stability over traditional LB models for rarefied flow simulations.

## Key findings

- High accuracy in shock tube and flow simulations
- Stable performance across wide Knudsen number range
- Significant improvement over conventional LB models

## Abstract

A novel discretization approach for the Bhatnager-Gross-Krook (BGK) kinetic equation is proposed. An hierarchy of LB models starting from $D1Q3$ model with increasing number of velocities converging to BGK model is derived. The method inherits properties of the Lattice Boltzmann (LB) method like linear streaming step, conservation of moments. Similar to the finite-difference methods for the BGK model the presented approach describes high-order moments of the distribution function with controllable error. The Sod shock tube problem, the Poiseuille flow between parallel plates and the plane Couette flow are considered for wide range of Knudsen numbers. Good stability and significant increase in precision over the conventional LB models are observed.