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’.

在这项工作中，我们开发了一个统一格子玻尔兹曼模型 (ULBM) 框架，可以无缝集成广泛使用的格子玻尔兹曼碰撞算子，包括 Bhatnagar-Gross-Krook 或单关系时间、多重松弛时间、中心矩或级联格子 Boltzmann 方法和多熵算子 (KBC)。这样的框架澄清了现有碰撞算子之间的关系，极大地方便了模型的比较和开发以及编码。重要的是，为特定碰撞算子构建的任何 LB 模型或处理方法都可以很容易地被其他算子采用。我们通过三个多相流动问题展示了 ULBM 框架的灵活性和强大功能：乳液的流变学、液滴在液膜上的飞溅和池沸腾的动力学。

本文是主题问题“流体动力学模拟中尺度方法的进展”的一部分。