Mirza Shahid, Niwalkar Amol, Gupta Ankit, Gautam Sneha, Anshul Avneesh, Bherwani Hemant, Biniwale Rajesh, Kumar Rakesh
CSIR-National Environmental Engineering Research Institute, Nagpur 440020, Maharashtra, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India.
Gondwana Res. 2023 Feb;114:40-54. doi: 10.1016/j.gr.2022.03.013. Epub 2022 Apr 8.
The current COVID-19 pandemic has underlined the importance of learning more about aerosols and particles that migrate through the airways when a person sneezes, coughs and speaks. The coronavirus transmission is influenced by particle movement, which contributes to the emergence of regulations on social distance, use of masks and face shield, crowded assemblies, and daily social activity in domestic, public, and corporate areas. Understanding the transmission of aerosols under different micro-environmental conditions, closed, or ventilated, has become extremely important to regulate safe social distances. The present work attempts to simulate the airborne transmission of coronavirus-laden particles under different respiratory-related activities, i.e., coughing and speaking, using CFD modelling through OpenFOAM v8. The dispersion coupled with the Discrete Phase Method (DPM) has been simulated to develop a better understanding of virus carrier particles transmission processes and their path trailing under different ventilation scenarios. The preliminary results of this study with respect to flow fields were in close agreement with published literature, which was then extended under varied ventilation scenarios and respiratory-related activities. The study observed that improper wearing of mask leads to escape of SARS-CoV-2 containminated aerosols having a smaller aerodynamic diameter from the gap between face mask and face, infecting different surfaces in the vicinity. It was also observed that aerosol propagation infecting the area through coughing is a faster phenomenon compared to the propagation of coronavirus-laden particles during speaking. The study's findings will help decision-makers formulate common but differentiated guidelines for safe distancing under different micro-environmental conditions.
当前的新冠疫情凸显了更多了解气溶胶以及人们打喷嚏、咳嗽和说话时在气道中传播的颗粒的重要性。冠状病毒的传播受颗粒运动影响，这促使了关于社交距离、口罩和面罩使用、人群聚集以及家庭、公共和企业场所日常社交活动的相关规定的出台。了解在封闭或通风等不同微环境条件下气溶胶的传播情况，对于规范安全社交距离变得极为重要。本研究试图通过OpenFOAM v8使用计算流体动力学（CFD）建模，模拟在不同与呼吸相关的活动（即咳嗽和说话）下携带冠状病毒颗粒的空气传播情况。已模拟了与离散相方法（DPM）耦合的扩散，以更好地理解病毒载体颗粒的传播过程及其在不同通风场景下的轨迹。这项关于流场的研究初步结果与已发表的文献密切相符，随后在不同通风场景和与呼吸相关的活动下进行了扩展。该研究观察到，口罩佩戴不当会导致空气动力学直径较小的含有新冠病毒的气溶胶从口罩与面部之间的缝隙逸出，感染附近的不同表面。还观察到，与说话时携带冠状病毒颗粒的传播相比，咳嗽时气溶胶传播感染该区域的现象更快。该研究结果将有助于决策者制定在不同微环境条件下安全社交距离的通用但有区别的指导方针。
