...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Building and Environment >Enhanced spread of expiratory droplets by turbulence in a cough jet
【24h】

Enhanced spread of expiratory droplets by turbulence in a cough jet

机译：咳嗽喷射中的湍流增强了呼气飞沫的扩散

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Coughing has been confirmed as a significant vector for transmitting respiratory diseases. It can be modelled physically as a turbulent jet to study the dispersion of expiratory droplets. The discrete random walk model for particle tracking is employed to study the effect of turbulence fluctuation on dispersion of particles and/or droplets. The concept of reach probability is proposed to characterise the streamwise spread distance. Our study shows that jet-like cough airflow turbulence prompts the wide spread of particles and expiratory droplets, and that the effect of evaporation on medium droplets (50 gm) is most significant. When turbulence fluctuations are considered for the 100 gm particles, there is a four-fold increase in the dispersion range in the streamwise direction, and a thirteen-fold increase in the transverse direction compared to that without fluctuation. Small particles are found to follow the airflow closely, dispersing in the whole jet region, while only 1% of large particles exceed 2 m in the streamwise direction; nearly 10% of medium particles travel 4.0 m (initial u(0) = 10 m/s, mouth diameter D = 2 cm). Droplets evaporate after being exhaled, but fates of small droplets with initial diameter d(p0) = 30 mu m as well as large droplets with d(p0) = 100 mu m are little affected by relative humidity (RH). The 30 mu m droplets evaporate in seconds and behave similarly to the 10 gm particles. The spread distance of large droplets is mainly determined by the jet outlet diameter and velocity. In contrast, the medium droplets are found to be very sensitive to RH under humid conditions (RH >= 80%). (C) 2015 Elsevier Ltd. All rights reserved.
机译：咳嗽已被证实是传播呼吸系统疾病的重要媒介。可以将其物理建模为湍流射流，以研究呼气液滴的散布。用于粒子跟踪的离散随机游走模型用于研究湍流波动对粒子和/或液滴分散的影响。提出了到达概率的概念来描述沿河方向的传播距离。我们的研究表明，喷流状的咳嗽气流湍流促使颗粒和呼气液滴的广泛散布，并且蒸发对中等液滴（50 gm）的影响最为显着。当考虑到100 gm颗粒的湍流波动时，与无波动的情况相比，沿流向的分散范围增加了4倍，而沿横向的分散范围增加了13倍。发现小颗粒紧紧跟随气流，并散布在整个射流区域，而只有1％的大颗粒在气流方向上超过2 m。几乎有10％的中型粒子行进4.0 m（初始u（0）= 10 m / s，口径D = 2 cm）。呼气后液滴蒸发，但初始直径d（p0）= 30μm的小液滴以及d（p0）= 100μm的大液滴的命运几乎不受相对湿度（RH）的影响。 30微米的液滴在几秒钟内蒸发，其行为与10克颗粒相似。大液滴的散布距离主要取决于射流出口直径和速度。相反，发现中等液滴在潮湿条件下对RH非常敏感（RH> = 80％）。 （C）2015 Elsevier Ltd.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号