An Alternative Lattice Boltzmann Model for Incompressible Flows and its Stabilization. (7th February 2017)

• Record Type: Journal Article
• Authors: Zhang, Liangqi; Zeng, Zhong; Xie, Haiqiong; Qiu, Zhouhua; Yao, Liping; Zhang, Yongxiang; Lu, Yiyu
• Is Part Of: Communications in computational physics. Volume 21:Number 2(2017:Feb.)
• Page Start: 443
• Page End: 465
• Publication Date: 2017-02-07
• Subjects: 47.10.ab, -- 47.11.-j, -- 02.60.Cb; Lattice Boltzmann method, -- incompressible flows, -- cavity flow, -- deviatoric stress, -- compressibility effect; Mathematical physics -- Data processing -- Periodicals; Physics -- Data processing -- Periodicals; 530.150285
• DOI: 10.4208/cicp.091014.030515a
• Languages: English
• ISSNs: 1815-2406

Abstract

Abstract: In this paper, an alternative lattice Boltzmann (LB)model for incompressible flows is proposed. By modifying directly the moments of the equilibrium distribution function (EDF), the continuous expression of the EDF in tensor Hermite polynomials is derived using the moment expansion and then discretizedwith the discrete velocity vectors of the D2Q9 lattice. The present model as well as its counterpart, the incompressible LB model proposed by Guo, reproduces the incompressible Navier-Stokes (N-S) equations for both steady and unsteady flows. Besides, an alternative pressure formula, which represents the pressure as the diagonal part of the stress tensor, is adopted in the present model. Furthermore, in order to enhance the stability of the present LB model, an additional relaxation time pertaining to the non-hydrodynamic mode is added to the BGK collision operator. The present LB model is validated by two benchmark tests: the cavity flow with different Reynolds number (Re) and the flow past an impulsively started cylinder at Re=40 and 550.