Characterizing the Dynamic Interactions and Exposure Implications of a Particle-Laden Cough Jet with Different Room Airflow Regimes Produced by Low and High Momentum Jets
Characterizing the Dynamic Interactions and Exposure Implications of a Particle-Laden Cough Jet with Different Room Airflow Regimes Produced by Low and High Momentum Jets
复制标题
表征含颗粒咳嗽喷射与低动量喷射和高动量喷射产生的不同室内气流状态的动态相互作用和暴露影响
DOI：
10.4209/aaqr.2015.03.0146
复制
发表时间：
2015-10-01
影响因子：
4
通讯作者：
Novoselac, Atila
中科院分区：
文献类型：
--
作者：
Cao, Guangyu;Liu, Shichao;Novoselac, Atila
这项研究的目的是考察考虑咳嗽颗粒的人与人之间的传输的线性狭缝扩散器所产生的不同室内气流分布与咳嗽射流的动态相互作用。实验测量是在一个房间里进行的，在那里，咳嗽射流和下行射流与不同动量的相互作用通过烟雾可视化。本文研究了与瞬变咳嗽射流和稳定下行射流的动态相互作用有关的参数：(1)咳嗽射流源与外露假人的距离；(2)下行平面射流的初始动量。实验结果表明，在头顶混合式通风系统中广泛应用的天花板附着式水平射流，存在着对咳嗽射流的偏转困难，从而难以减少咳嗽颗粒的人与人之间的传输。这项研究发现，向下的飞机喷射可以阻止咳嗽颗粒从咳嗽假人到ED的运输。当教育署站在距离咳嗽假人0.5米远的地方时，使用向下的平面喷射器，个人接触咳嗽粒子的水平可比使用天花板附设的水平喷射器低两个数量级。此外，这项研究量化了咳嗽喷射器和向下飞机喷射器在减少接触咳嗽颗粒的能力方面的相互作用。这一结果可用于扩散器的选择过程，并表明在公共场所采用高速下行平面射流的通风系统可能有助于减少人与人之间对咳嗽颗粒物的暴露。
The objective of this study is to examine the dynamic interaction of a cough jet with different indoor airflow distributions created by linear slot diffusers considering the inter-personal transport of coughed particles. The experimental measurements were performed in a chamber, where the interaction of a cough jet and downward jets with various momentums was visualized by smoke. In this study, parameters related to the dynamic interaction of a transient cough jet and a steady downward jet have been studied: (1) distance between the cough jet source and an exposed dummy (ED); (2) the initial momentum of the downward plane jet. The experimental results indicate that the ceiling-attached horizontal jets that are widely applied in the over-head mixing ventilation systems have difficulties in deflecting the cough jet, and thereby have difficulties in reducing inter-personal transport of the coughed particles. This study found that a downward plane jet could prevent the transport of cough particles from the cough dummy to the ED. When the ED is standing 0.5 meter away from the cough dummy, the personal exposure (PE) level to coughed particles by using a downward plane jet could be two orders of magnitude lower than by using ceiling-attached horizontal jets. In addition, this study quantifies the interaction of a cough jet and a downward plane jet in their ability to reduce exposure to coughed particles. The results may be used in the process of diffuser selection and suggests that ventilation systems employing downward plane jets with high discharge velocities might be useful in public spaces to reduce inter-personal exposure to coughed particles.