| Abstract: | Numerical instability may occur when simulating high Reynolds number
flows by the lattice Boltzmann method (LBM). The multiple-relaxation-time (MRT)
model of the LBM can improve the accuracy and stability, but is still subject to numerical
instability when simulating flows with large single-grid Reynolds number
(Reynolds number/grid number). The viscosity counteracting approach proposed recently
is a method of enhancing the stability of the LBM. However, its effectiveness
was only verified in the single-relaxation-time model of the LBM (SRT-LBM). This paper
aims to propose the viscosity counteracting approach for the multiple-relaxation-time
model (MRT-LBM) and analyze its numerical characteristics. The verification is
conducted by simulating some benchmark cases: the two-dimensional (2D) lid-driven
cavity flow, Poiseuille flow, Taylor-Green vortex flow and Couette flow, and three-dimensional
(3D) rectangular jet. Qualitative and Quantitative comparisons show that
the viscosity counteracting approach for the MRT-LBM has better accuracy and stability
than that for the SRT-LBM. |
