Abstract The fundamental understanding of the multiphase phenomena involved in drying of porous media is still a challenging task. Pore network models (PNMs) reveal the micro–macro interactions. However, PNMs have shortfalls in using true geometry, and in revealing capillary instabilities and film-effects. In this work, Shan Chen representation of Lattice Boltzmann Method (LBM) is applied to elucidate such complicated multiphase phenomena, i.e. micro-scale-dynamics evolution during drying. In a bundle of capillaries, liquid transport is explained with two pressure gradients. First, the pressure gradient between capillaries leading to capillary pumping, second, the pressure gradient within each capillary along the liquid–gas interface resulting in formation of hydraulic films. Transformation of hydraulic films to adsorbed films is revealed in irregular pore structures. Peclet number is employed to elucidate the effect of boundary layer thickness and temperature on drying kinetics. Characteristics of drying are re-established using the LBM for pore structures with bimodal size distribution.

中文翻译：

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毛细管束等温干燥过程中微观-宏观相互作用的格子 Boltzmann 模拟

摘要 对多孔介质干燥中涉及的多相现象的基本理解仍然是一项具有挑战性的任务。孔隙网络模型 (PNM) 揭示了微观-宏观相互作用。然而，PNM 在使用真实几何形状以及揭示毛细管不稳定性和薄膜效应方面存在不足。在这项工作中，采用格子玻尔兹曼方法 (LBM) 的 Shan Chen 表示来阐明这种复杂的多相现象，即干燥过程中的微观尺度动力学演变。在一束毛细管中，液体传输用两个压力梯度来解释。首先，毛细管之间的压力梯度导致毛细管泵送，其次，每个毛细管内沿液-气界面的压力梯度导致液压膜的形成。在不规则的孔隙结构中揭示了水硬膜向吸附膜的转变。Peclet 数用于阐明边界层厚度和温度对干燥动力学的影响。对于具有双峰尺寸分布的孔隙结构，使用 LBM 重新建立干燥特性。