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Journal of ZheJiang University (Engineering Science)  2022, Vol. 56 Issue (1): 161-167    DOI: 10.3785/j.issn.1008-973X.2022.01.018
    
Dispersion characteristics of droplet in bus and risk prediction of infection
Ya-feng YANG1(),Yi-ping WANG1,*(),Zhi-xin CHEN1,Jian-jun SU2,Bin YANG3
1. Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan 430070, China
2. Hubei Qixing Cabin Manufacturing Limited Company, Suizhou 441300, China
3. Gansu Construction Investment Heavy Industry Technology Limited Company, Lanzhou 730000, China
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Abstract  

The bus with air-condition was chosen as research object in order to analyze the dispersion of droplet in bus and reveal the mechanism of virus transmission. The dispersion characteristic parameters of droplet such as dispersion path, concentration distribution and escape rate were obtained by the analysis of flow field. The calculation of transport of the droplets exhaled from a single cough by patient in the front, middle and back of the cabin with the Lagrangian method. Then the infection risk for passenger can be evaluated by the Wells-Riley equation according to the amount of inhaled virus particles by passenger. Results show that location of the patient and air return opening, the airflow pattern can significantly affect the droplet distribution. The patient in the front may cause more passengers at a higher infection risk compared with the patient in the back. The infection probability of passengers located in the droplet dispersion pathway and within three rows of the patient is higher than 30%.



Key wordsbus      droplet      risk prediction of infection      computational fluid dynamics (CFD)      Wells-Riley equation     
Received: 15 March 2021      Published: 05 January 2022
CLC:  TB 71  
Fund:  国家自然科学基金资助项目(51775395);国家重点研发计划资助项目(2018YFB0105301)
Corresponding Authors: Yi-ping WANG     E-mail: yyfyfq@whut.edu.cn;wangyiping@whut.edu.cn
Cite this article:

Ya-feng YANG,Yi-ping WANG,Zhi-xin CHEN,Jian-jun SU,Bin YANG. Dispersion characteristics of droplet in bus and risk prediction of infection. Journal of ZheJiang University (Engineering Science), 2022, 56(1): 161-167.

URL:

https://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2022.01.018     OR     https://www.zjujournals.com/eng/Y2022/V56/I1/161


大巴车飞沫扩散特性及乘客感染风险预测

为了研究飞沫在大巴车中的扩散特性并揭示病毒的传播规律,以空调开启状态下的大巴车为研究对象,通过对车内流场结构的分析,应用拉格朗日方法对位于车内前部、中部、后部的患者咳嗽产生飞沫的扩散过程进行计算,获取飞沫的传播路径、浓度分布、逃逸速率等扩散特性参数. 根据飞沫中病毒颗粒数量,结合Wells-Riley方程对车内乘客的感染概率进行预测. 研究结果表明,飞沫在舱内的分布特性与患者位置、回风口位置、气流组织等因素密切相关;与位于后部患者相比,前部患者会使更多的乘客面临较高的感染风险;位于飞沫扩散路径且距离患者三排以内的乘客感染概率均高于30%.


关键词: 大巴车,  飞沫,  感染风险预测,  计算流体动力学(CFD),  Wells-Riley方程 
Fig.1 Bus seat arrangement
Fig.2 Bus air supply arrangement
Fig.3 Passenger breathing area
边界条件 设置值
送风口 送风速度为3 m/s,温度20 ℃,垂直送风口.
湍流强度为2.5%,湍流尺度为0.005 m.
回风口 压力出口,0 Pa.
人体表面 人体热流密度为20 W/m2
天花板、地板、车身 热交换系数为3 W/(m2·K)
玻璃 热交换系数为5 W/(m2·K)
其余壁面 绝热
Tab.1 Settings of boundary conditions
设置项 设定值
湍流模型 RNGk-ε
壁面函数 标准壁面函数
空间离散格式 二阶迎风格式
计算方法 SIMPLE算法
Tab.2 Settings of solver
X方向截面 面平均流速/(m·s?1
330万 710万 1800万
1.5 m 0.190 0.187 0.192
4.5 m 0.179 0.185 0.176
8.5 m 0.223 0.220 0.212
Tab.3 Verification of grid independence
Fig.4 Velocity distribution of steady state flow field
Fig.5 Temporal distributions of droplets in case 1
Fig.6 Temporal distributions of droplets in case 2
Fig.7 Temporal distributions of droplets in case 3
Fig.8 Droplets escape rate
Fig.9 Probability of passenger infection in three cases
[1]   World Health Organization, 2020a. Disease outbreaks [EB/OL]. (2020-02-05). https://www.who.int/emergencies/diseases/en/.
[2]   World Health Organization, 2020b. Novel coronavirus (2019-nCoV) situation reports [EB/OL]. (2020-02-05). https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-report/.
[3]   MORAWSKA L Droplet fate in indoor environments, or can we prevent the spread of infection?[J]. Indoor Air, 2010, 16 (5): 335- 347
[4]   ANNIE B, SACHA S A, CHARLES R B, et al The roles of transportation and transportation hubs in the propagation of influenza and coronaviruses: a systematic review[J]. Journal of Travel Medicine, 2016, 23 (1): 1- 7
doi: 10.1093/jtm/tav014
[5]   NASIR Z A, CAMPOS L C, CHRISTIE N, et al Airborne biological hazards and urban transport infrastructure: current challenges and future directions[J]. Environmental Science and Pollution Research International, 2016, 23 (15): 15757- 15766
doi: 10.1007/s11356-016-7064-8
[6]   BINNS P L, SHEPPEARD V, STAFF M P Isolation and quarantine during pandemic (H1N1) 2009 influenza in NSW: the operational experience of public health units[J]. New South Wales Public Health Bulletin, 2010, 21 (2): 10- 15
doi: 10.1071/NB09036
[7]   SHEN Y, LI C, DONG H, et al Community outbreak investigation of SARS-CoV-2 transmission among bus riders in Eastern China[J]. JAMA Internal Medicine, 2020, 180 (12): 1665- 1671
doi: 10.1001/jamainternmed.2020.5225
[8]   ZHU S, SREBRIC J, SPENGLER J D, et al An advanced numerical model for the assessment of airborne transmission of influenza in bus microenvironments[J]. Building and Environment, 2012, 47 (1): 67- 75
[9]   YANG X, OU C, YANG H, et al Transmission of pathogen-laden expiratory droplets in a coach bus[J]. Journal of Hazardous Materials, 2020, 397: 122609
doi: 10.1016/j.jhazmat.2020.122609
[10]   ZHANG Z, HAN T, YOO K H, et al Disease transmission through expiratory aerosols on an urban bus[J]. Physics of Fluids, 2021, 33: 015116
doi: 10.1063/5.0037452
[11]   XIE X, LI Y, SUN H, et al Exhaled droplets due to talking and coughing[J]. Journal of the Royal Society Interface, 2009, 6 (Supple.6): S703- S714
[12]   LI F, LIU J, PEI J, et al Experimental study of gaseous and particulate contaminants distribution in an aircraft cabin[J]. Atmospheric Environment, 2014, 85: 223- 233
doi: 10.1016/j.atmosenv.2013.11.049
[13]   WANG F, YAT H Y, WEN B N, et al Improvement of the indoor environment and airborne contamination control in an operating room[J]. Advanced Materials Research, 2011, 255-260: 1532- 1536
doi: 10.4028/www.scientific.net/AMR.255-260.1532
[14]   CHEN Q Comparison of different k-ε models for indoor air flow computations[J]. Numerical Heat Transfer Fundamentals, 1995, 28 (3): 353- 369
doi: 10.1080/10407799508928838
[15]   CHEN Q Prediction of room air motion by Reynolds-stress models[J]. Building and Environment, 1996, 31 (3): 233- 244
doi: 10.1016/0360-1323(95)00049-6
[16]   CHEN Q, XU W A zero-equation turbulence model for indoor airflow simulation[J]. Energy and Buildings, 1998, 28 (2): 137- 144
doi: 10.1016/S0378-7788(98)00020-6
[17]   ZHANG Z, CHEN Q Comparison of the Eulerian and Lagrangian methods for predicting particle transport in enclosed spaces[J]. Atmospheric Environment, 2007, 41 (25): 5236- 5248
doi: 10.1016/j.atmosenv.2006.05.086
[18]   WELLS W F. Airborne contagion and air hygiene: an ecological study of droplet infection [M]. Cambridge: Harvard University Press, 1955.
[19]   RILEY E C, MURPHY G, RILEY R L Airborne spread of measles in a suburban elementary school[J]. American Journal of Epidemiology, 1978, 107 (5): 421- 432
doi: 10.1093/oxfordjournals.aje.a112560
[20]   ZHU S, KATO S, YANG J Study on transport characteristics of saliva droplets produced by coughing in a calm indoor environment[J]. Building and Environment, 2006, 41 (12): 1691- 1702
doi: 10.1016/j.buildenv.2005.06.024
[21]   GUPTA J K, LIN C H, CHEN Q Flow dynamics and characterization of a cough[J]. Indoor Air, 2009, 19 (6): 517- 525
doi: 10.1111/j.1600-0668.2009.00619.x
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