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ARTICLE

Optimization of the Multiple-Relaxation-Time Micro-Flow Lattice Boltzmann Method

Kazuhiko Suga¹, Takahiko Ito¹

1 Osaka Prefecture University, Osaka, Japan

Structural Longevity 2011, 5(3), 157-160. https://doi.org/10.3970/sl.2011.005.157

Abstract

Evaluation and optimization of the multiple-relaxation-time (MRT) lattice Boltzmann method for micro-flows (µ-flow LBM) are performed with the two-dimensional nine discrete velocity (D2Q9) model. The MRT µ-flow LBM consisting of the combination of bounce-back and full diffusive (CBBFD) wall boundary condition is considered. Based on the discussion of Chai et al. (2010), the presently applied CBBFD model and relaxation time for heat flux τ_q satisfy the second-order slip boundary condition. However, modification to the MRT model of Chai et al. (MRT-C) is made to the relaxation time for the moments related to the stress τ_s by introducing the psi function (Stops,1970; Guo et al., 2006). This modified MRT-C model (MRT-Cm1) and further modified model (MRT-Cm2) by changing the coefficients of the second-order slip velocity to the coefficients of Mitsuya (1993) are evaluated. As shown in Fig.1, since the MRT-Cm2 model performs best among the evaluated models including the one by Verhaeghe et al. (MRT-V) in predicting slip velocities and flow rates of Poiseuille flows in the range of Knudsen number 0.01

Keywords

lattice Boltzmann method, Knudsen number, molecular dynamics simulation, Poiseuille flow, obstacle flow.

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Cite This Article

Suga, K., Ito, T. (2011). Optimization of the Multiple-Relaxation-Time Micro-Flow Lattice Boltzmann Method. Structural Longevity, 5(3), 157–160. https://doi.org/10.3970/sl.2011.005.157

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