Enhanced lattice Bhatnagar-Gross-Krook method for fluid dynamics simulation

TL;DR

This paper introduces an enhanced LBGK model for fluid dynamics that improves stability and accuracy while maintaining computational efficiency, by accounting for non-hydrodynamic mode relaxation.

Contribution

A generalized LBGK model that incorporates frame-independent relaxation of non-hydrodynamic modes, improving simulation stability and accuracy.

Findings

Enhanced stability over standard LBGK

Improved accuracy in shear layer simulations

Retains computational efficiency

Abstract

A generalization of the lattice Bhatnagar-Gross-Krook (LBGK) model for the simulation of hydrodynamics is presented, which takes into account the difference and the frame-independence of the relaxation of non-hydrodynamic modes. The present model retains the computationally efficient standard LBGK form with the generalized equilibrium explicitly derived. The two-dimensional realization on the standard lattice is discussed in detail. Performance of the model is assessed through a shear layer simulation and enhanced stability and accuracy with respect to the standard LBGK are reported. The results demonstrate that the present model is a useful upgrade of the standard LBGK without compromising its computational efficiency and accuracy.