Effectiveness of RANS in predicting indoor airborne viral transmission: A critical evaluation against LES
Effectiveness of RANS in predicting indoor airborne viral transmission: A critical evaluation against LES
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DOI：
10.1016/j.compfluid.2023.105845
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发表时间：
2023-03-14
影响因子：
2.8
通讯作者：
Balachandar，S.
中科院分区：
文献类型：
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作者：
Choudhary，K.;Krishnaprasad，K. A.;Balachandar，S.
我们研究了尺寸为 10× 10× 3. 2 m 3 的标准房间内液滴核的扩散情况，房间的天花板中央放置了四路卡式空调机组。我们使用雷诺平均纳维斯托克斯 (RANS) 模拟，三种流速对应于每小时换气次数 (ACH) 值 2.5、5 和 10。房间设置和操作条件的选择与最近的高保真大涡模拟 (LES) 研究相匹配。我们使用统计过载，总共一百万个液滴核最初以均匀的概率随机分布在房间内。考虑半径范围为 0.1 至 10 μm 的六种核尺寸（每个尺寸 166,667 个核）。模拟是单向耦合的，并使用 Langevin 方程来模拟子网格运动。将流量和粒子统计数据与参考 LES 模拟进行比较，我们发现 RANS k−ɛ 可实现模型可用作 LES 的计算成本更便宜的替代方案，用于预测有限空间中的病原体浓度，尽管可能会增加统计差异。
We investigate the dispersal of droplet nuclei inside a canonical room of size 10× 10× 3. 2 m 3 with a four-way cassette air-conditioning unit placed at the center of the ceiling. We use Reynolds averaged Navier–Stokes (RANS) simulations with three flow rates corresponding to air changes per hour (ACH) values of 2.5, 5, and 10. The room setup as well as the operating conditions are chosen to match those of a recent high-fidelity large eddy simulation (LES) study. We use statistical overloading with a total of one million droplet nuclei being initially distributed randomly with uniform probability within the room. Six nuclei sizes are considered ranging in radius from 0.1 to 10 μ m (166,667 nuclei per size). The simulations are one-way coupled and employ the Langevin equations to model sub-grid motion. The flow and particle statistics are compared against the reference LES simulations, and we find that the RANS k− ɛ realizable model may be used as a computationally cheaper alternative to LES for predicting pathogen concentration in confined spaces albeit, with potentially increased statistical discrepancy.