Fibrous filter media are commonly used to remove airborne particles that are harmful to human health and the environment. Although filter media are often multilayered for various reasons, no systematic study of the impact of multilayering on filter media performance has been reported. In this paper, direct numerical simulations with the lattice Boltzmann method are used in order to shed light on the impact of multilayering on the performance of clean bimodal fibrous filter media in a Stokes flow regime. Virtual model clean filter media with up to eight layers and various fibre formulations are compared in terms of permeability or pressure drop, capture efficiency, and quality factor. A careful analysis of the results revealed that multilayering had no statistically significant impact on the performance of the clean filter media. At best, the impact of multilayering was similar to that of the inherent variability of such random structures. Fibre formulation was found to be a more efficient way of improving the performance of the filter media. Placing interlayered air gaps between fibrous layers also slightly improved the quality factor by facilitating the flow at the interfaces of the fibrous layers. These findings will guide future studies on the performance of multilayered filters with more complex flow conditions, such as those encountered with inertial or nanofibre‐made filter media and with the fouling of filter media.

中文翻译：

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多层结构对清洁空气过滤介质过滤性能的影响

纤维过滤介质通常用于去除对人体健康和环境有害的空气传播颗粒。尽管由于各种原因常常使过滤介质多层化，但尚未有关于多层化对过滤介质性能影响的系统研究的报道。在本文中，使用格子Boltzmann方法进行直接数值模拟，以阐明在斯托克斯流态下多层结构对干净的双峰纤维过滤介质性能的影响。比较具有多达八层和各种纤维配方的虚拟模型清洁过滤器介质的渗透率或压降，捕获效率和品质因数。对结果的仔细分析显示，多层清洁滤纸的性能没有统计学上的显着影响。最好，多层的影响类似于这种随机结构的固有变异性。发现纤维配方是改善过滤介质性能的更有效方法。通过促进在纤维层的界面处的流动，在纤维层之间放置层间气隙还稍微改善了品质因数。这些发现将指导未来对流动条件更为复杂的多层过滤器性能的研究，例如惯性或纳米纤维制成的过滤介质以及过滤介质的结垢。通过促进在纤维层的界面处的流动，在纤维层之间放置层间气隙还稍微改善了品质因数。这些发现将指导未来对流动条件更为复杂的多层过滤器性能的研究，例如惯性或纳米纤维制成的过滤介质以及过滤介质的结垢。通过促进在纤维层的界面处的流动，在纤维层之间放置层间气隙还稍微改善了品质因数。这些发现将指导未来对流动条件更为复杂的多层过滤器性能的研究，例如惯性或纳米纤维制成的过滤介质以及过滤介质的结垢。