Abstract Porous materials used in constructions and many other daily activities tend to have a strong affinity towards external fluids, especially moist air, which accumulates in the porous media leading to physical and mechanical effects. For wood based materials, moisture transport dynamics is a function of relative humidity, temperature and sorption history. Coupling of these three parameters has not been fully captured in many of the existing numerical models, which usually make use of the classical forms of Fick’s and Fourier’s laws. A thermodynamic approach based on the hybrid mixture theory is therefore used in this work to provide a system of consistent coupled equations that incorporate multi-component processes of: Fickian-like diffusion of vapor, Darcy-like seepage of gas and Fourier-like heat transport. The sorption process is driven by the difference in chemical potential between the bound water and local vapor in the material, and governed by sorption isotherms implemented along with Frandsen’s hysteresis model. The result is a thermodynamically consistent model, which is implicitly capable of modeling inherent hygrothermal properties including the heat of sorption. Numerical examples are implemented in a finite element method framework to describe the performance of the model in simulating moisture and heat transport dynamics in a wood section.

中文翻译：

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使用混合混合理论模拟木材中的瞬态和滞后湿热过程

摘要 建筑和许多其他日常活动中使用的多孔材料往往对外部流体具有很强的亲和力，尤其是潮湿的空气，这些流体积聚在多孔介质中，导致物理和机械效应。对于木质材料，水分输送动力学是相对湿度、温度和吸附历史的函数。这三个参数的耦合在许多现有的数值模型中没有被完全捕获，这些模型通常使用 Fick 和傅立叶定律的经典形式。因此，在这项工作中使用基于混合混合物理论的热力学方法提供了一个一致耦合方程系统，该系统包含以下多组分过程：Fickian-like 蒸汽扩散、Darcy-like 气体渗流和 Fourier-like 热传递. 吸附过程由材料中结合水和局部蒸汽之间的化学势差驱动，并由与 Frandsen 滞后模型一起实施的吸附等温线控制。结果是一个热力学一致的模型，它隐含地能够模拟固有的湿热特性，包括吸附热。在有限元方法框架中实施了数值示例，以描述模型在模拟木材截面中的水分和热传输动力学方面的性能。它隐含地能够模拟固有的湿热特性，包括吸附热。在有限元方法框架中实施了数值示例，以描述模型在模拟木材截面中的水分和热传输动力学方面的性能。它隐含地能够模拟固有的湿热特性，包括吸附热。在有限元方法框架中实施了数值示例，以描述模型在模拟木材截面中的水分和热传输动力学方面的性能。