A critical factor affecting the accuracy of Computational Fluid Dynamic (CFD) simulations and the time required to conduct them is construction of the computational mesh. This study aimed to evaluate the relatively new polyhedral mesh style for simulating aerosol deposition in the upper conducting airways compared with established meshing techniques and experimental data. Hexahedral and polyhedral mesh solutions were compared in two benchmark geometries: 1) a 90°-bend with flow characteristics similar to the extrathoracic airways of an adolescent child, and 2) a double bifurcation representing bifurcations B3–B5 in an adult. Both 4-block and 5-block hexahedral meshes were used in the 90°-bend to capture the potential of fully-structured hexahedral meshes. In the 90°-bend, polyhedral elements matched polydisperse in vitro deposition data with 20% relative error (RE; averaged across the particle sizes considered), which is an improvement on the accuracy of the 4-block hexahedral mesh (35% RE) and is similar to the accuracy of the 5-block hexahedral mesh (19% RE). In the double bifurcation, deposition fraction relative differences evaluated between polyhedral and hexahedral meshes ranged from 0.3% to 28.6% for the different particle sizes assessed, which is an order of magnitude improvement compared with previous studies that considered hexahedral vs. hybrid tetrahedral-prism meshes for the same flow field. Solution convergence time with polyhedral elements was found to be 50%–140% higher than with hexahedral meshes of comparable size. While application dependent, the increase in simulation time observed with polyhedral meshes will likely be outweighed by the ease and convenience of polyhedral mesh construction. It was concluded that the polyhedral mesh style, with sufficient resolution especially near the walls, is an excellent alternative to the highly regarded hexahedral mesh style for predicting upper airway aerosol transport and deposition, providing a powerful new tool for the assessment of respiratory aerosol dosimetry.

影响计算流体动力学 (CFD) 模拟的准确性和执行模拟所需时间的一个关键因素是计算网格的构造。本研究旨在与已建立的网格划分技术和实验数据相比，评估用于模拟上导气道气溶胶沉积的相对较新的多面体网格样式。在两个基准几何结构中比较六面体和多面体网格解决方案：1) 90° 弯曲，其流动特性类似于青春期儿童的胸腔外气道，以及 2) 双分叉代表成人的分叉 B3–B5。4 块和 5 块六面体网格都用于 90° 弯曲，以捕捉完全结构化六面体网格的潜力。在 90° 弯曲中，多面体元素在体外与多分散相匹配具有 20% 相对误差的沉积数据（RE；考虑的粒径的平均值），这是对 4 块六面体网格（35% RE）精度的改进，与 5 块六面体网格的精度相似（19% 稀土）。在双分叉中，对于所评估的不同粒径，多面体和六面体网格之间的沉积分数相对差异评估范围为 0.3% 至 28.6%，与之前考虑六面体与混合四面体棱柱网格的研究相比，这是一个数量级的改进对于同一个流场。发现多面体单元的解收敛时间比大小相当的六面体网格高 50%–140%。虽然依赖于应用程序，使用多面体网格观察到的模拟时间的增加可能会被多面体网格构造的简单性和便利性所抵消。得出的结论是，多面体网格样式具有足够的分辨率，尤其是在壁附近，是备受推崇的六面体网格样式的绝佳替代品，可用于预测上呼吸道气溶胶传输和沉积，为评估呼吸气溶胶剂量学提供了强大的新工具。