Lattice Boltzmann Scheme associated with flexible Prandtl number and specific heat ratio based on the polyatomic ES-BGK model

TL;DR

This paper introduces a lattice Boltzmann scheme based on the polyatomic ES-BGK model that allows flexible adjustment of Prandtl number and specific heat ratio, verified through benchmark tests.

Contribution

It develops a novel lattice Boltzmann scheme incorporating polyatomic ES-BGK model with adjustable Prandtl number and heat ratio, expanding the flexibility of fluid simulations.

Findings

Numerical results agree well with analytical solutions.

The scheme effectively adjusts Prandtl number and heat ratio.

Benchmark tests validate the scheme's accuracy.

Abstract

A lattice Boltzmann scheme associated with flexible Prandtl number and specific heat ratio is proposed, which is based on the polyatomic ellipsoidal statistics model(ES-BGK). The Prandtl number can be modified by a parameter of the Gaussian distribution and the specific heat ratio can be modified by additional free degrees. For the sake of constructing the scheme proposed, the Gaussian distribution is expanded on the Hermite polynomials and the general term formula for the Hermite coefficients of the Gaussian distribution is deduced. Benchmarks are carried out to verify the scheme proposed. The numerical results are in good agreement with the the analytical solutions.