Lattice-Boltzmann model for axisymmetric thermal flows

TL;DR

This paper introduces a simplified thermal lattice-Boltzmann model for axisymmetric flows that maintains numerical stability and accurately predicts heat transfer in circular ducts and annular convection.

Contribution

A new, simpler axisymmetric thermal LB model based on double-distribution-function approach that improves upon existing models in stability and simplicity.

Findings

Nusselt numbers match analytical and previous results

Model effectively simulates laminar and natural convection flows

Numerical results validate the model's accuracy

Abstract

In this brief report, a thermal lattice-Boltzmann (LB) model is presented for axisymmetric thermal flows in the incompressible limit. The model is based on the double-distribution-function LB method, which has attracted much attention since its emergence for its excellent numerical stability. Compared with the existing axisymmetric thermal LB models, the present model is simpler and retains the inherent features of the standard LB method. Numerical simulations are carried out for the thermally developing laminar flows in circular ducts and the natural convection in an annulus between two coaxial vertical cylinders. The Nusselt number obtained from the simulations agrees well with the analytical solutions and/or the results reported in previous studies.