Finite Volume $vs.$ Streaming-based Lattice Boltzmann algorithm for fluid-dynamics simulations: a one-to-one accuracy and performance study

TL;DR

This paper presents a systematic comparison between a new finite volume Lattice Boltzmann method and the standard streaming approach, evaluating accuracy and performance in fluid dynamics simulations, including turbulent thermal flows.

Contribution

It introduces a high-accuracy finite volume LB algorithm and provides the first comprehensive comparison with the standard method, including complex turbulent thermal flows.

Findings

FV method achieves comparable accuracy to streaming

FV method demonstrates competitive computational performance

Successful simulation of high-Rayleigh number turbulent convection

Abstract

A new finite volume (FV) discretisation method for the Lattice Boltzmann (LB) equation which combines high accuracy with limited computational cost is presented. In order to assess the performance of the FV method we carry out a systematic comparison, focused on accuracy and computational performances, with the standard $streaming$ (ST) Lattice Boltzmann equation algorithm. To our knowledge such a systematic comparison has never been previously reported. In particular we aim at clarifying whether and in which conditions the proposed algorithm, and more generally any FV algorithm, can be taken as the method of choice in fluid-dynamics LB simulations. For this reason the comparative analysis is further extended to the case of realistic flows, in particular thermally driven flows in turbulent conditions. We report the first successful simulation of high-Rayleigh number convective flow performed by a Lattice Boltzmann FV based algorithm with wall grid refinement.