A novel gas diffusivity model for dry porous media with a damaged tree-like branching network is proposed by using the fractal theory in this study. We systematically investigated the effects of the number of damaged channels and the other structural parameters on the dimensionless gas diffusivity (DGD) and concentration drop. As the number of damaged channels increases, the DGD presents a decreasing trend, while the ratio of concentration drop shows a rising tendency. Meanwhile, the DGD is negatively correlated to the length exponent, the total number of branching levels, and the branching angle, respectively. On the other hand, the DGD is positively correlated with the diameter exponent. Besides, the ratio of concentration drop is negatively correlated with the length exponent and the total number of branching levels. However, it is positively associated with the diameter exponent and branching levels. In addition, during the calculation of the value of concentration drop, the total concentration drop can be disassembled into two equal-ratio sequences. And the scale factors in sequences are constants that are independent of the number of damaged channels. The reliability of the model predictions was verified by a comparison with the experimental data available in the literature. The physical mechanism of gas diffusion in the damaged network may be well explained by the proposed model.

本研究利用分形理论，提出了一种新的具有受损树状分支网络的干燥多孔介质的气体扩散率模型。我们系统地研究了受损通道数量和其他结构参数对无量纲气体扩散率 (DGD) 和浓度下降的影响。随着受损通道数量的增加，DGD呈下降趋势，而浓度下降比呈上升趋势。同时，DGD 分别与长度指数、分支层数和分支角度呈负相关。另一方面，DGD 与直径指数正相关。此外，浓度下降的比率与长度指数和分支水平的总数呈负相关。然而，它与直径指数和分支水平正相关。此外，在计算浓度下降值时，可以将总浓度下降分解为两个等比序列。并且序列中的比例因子是常数，与损坏通道的数量无关。通过与文献中可用的实验数据进行比较，验证了模型预测的可靠性。所提出的模型可以很好地解释受损网络中气体扩散的物理机制。并且序列中的比例因子是常数，与损坏通道的数量无关。通过与文献中可用的实验数据进行比较，验证了模型预测的可靠性。所提出的模型可以很好地解释受损网络中气体扩散的物理机制。并且序列中的比例因子是常数，与损坏通道的数量无关。通过与文献中可用的实验数据进行比较，验证了模型预测的可靠性。所提出的模型可以很好地解释受损网络中气体扩散的物理机制。