A unified lattice Boltzmann model and application to multiphase flows

Abstract

In this work, we develop a unified lattice Boltzmann model (ULBM) framework that can seamlessly integrate the widely used lattice Boltzmann collision operators, including the Bhatnagar–Gross–Krook or single-relation-time, multiple-relaxation-time, central-moment or cascaded lattice Boltzmann method and multiple entropic operators (KBC). Such a framework clarifies the relations among the existing collision operators and greatly facilitates model comparison and development as well as coding. Importantly, any LB model or treatment constructed for a specific collision operator could be easily adopted by other operators. We demonstrate the flexibility and power of the ULBM framework through three multiphase flow problems: the rheology of an emulsion, splashing of a droplet on a liquid film and dynamics of pool boiling. Further exploration of ULBM for a wide variety of phenomena would be both realistic and beneficial, making the LBM more accessible to non-specialists. This article is part of the theme issue ‘Progress in mesoscale methods for fluid dynamics simulation’.

Droplet evaporation in finite-size systems: Theoretical analysis and mesoscopic modeling

“…where F is the total force exerted on the fluid. Various collision models can be chosen to suit the problems under investigation, which have been reviewed in detail and can be integrated into a unified framework [21]. In the present work, we use the cascaded collision model [41], which possesses very good numerical stability and therefore helps to conduct simulations at large liquid-vapor density ratios.…”

“…1). Recently, the mesoscopic lattice Boltzmann (LB) method has been used more and more widely for studying evaporation dynamics [6,8,[16][17][18][19], mainly due to its advantages of natural incorporation of micro/mesoscale physics, easy treatment of liquid-vapor interface, and highly efficient algorithm [20][21][22][23]. Ledesma-Aguilar et al [16] applied a phase-field LB method to simulate sessile droplet evaporation, driven by a concentration gradient, by manipulating the order parameter at the boundary to induce a chemical potential gradient.…”

Dynamic behavior of droplet transport on realistic gas diffusion layer with inertial effect via a unified lattice Boltzmann method

“…According to the scheme of collision process, the LB model can be classified into several categories, such as single-relaxation-time (SRT) [46], multi-relaxation-time (MRT) [47] and non-orthogonal MRT LB model [48,49], which has recently been put into an unified lattice Boltzmann model (ULBM) framework [50]. The present paper focuses on the non-orthogonal MRT LB model, which simplifies the mapping matrix between the velocity space and moment space and shows good transportability and great flexibility among the lattice schemes.…”

“…The LB equation including evolution and collision process within the ULBM framework can be expressed as [50]…”

An efficient thermal lattice Boltzmann method for simulating three-dimensional liquid-vapor phase change

“…They can not be directly used for the 3D liquid-vapor phase change problems due to the significant differences in the development and implementation of 3D LB models. These above issues may also be why the finite-difference method (FDM) is still the most widely used approach in LB community for modeling 3D liquid-vapor phase change today [26][27][28][29][30]. More recently, Fogliatto et al [31] developed a multiple-relaxation-time (MRT) LB model for boiling heat transfer with the assumption of the uniform distribution of the specific heat at constant volume.…”