Li Xian, Feng Bujin
School of Civil Engineering and Architecture, Linyi University, Linyi, 276000, China.
College of Agriculture, Shandong Agricultural University, Taian, 271018, China.
Build Environ. 2023 May 15;236:110261. doi: 10.1016/j.buildenv.2023.110261. Epub 2023 Apr 1.
The recent outbreak of COVID-19 has threatened public health. Owing to the relatively sealed environment and poor ventilation in elevator cabins, passengers are at risk of respiratory tract infection. However, the distribution and dispersion of droplet aerosols in elevator cabins remain unclear. This study investigated the transmission of droplet aerosols exhaled by a source patient under three ventilation modes. Droplet aerosols produced by nose breathing and mouth coughing were resolved using computational fluid dynamics (CFD) simulations. We adopted the verified renormalization group (RNG) - turbulence model to simulate the flow field and the Lagrangian method to track the droplet aerosols. In addition, the influence of the ventilation mode on droplet transmission was evaluated. The results showed that droplet aerosols gathered in the elevator cabin and were difficult to discharge under the mixed and displacement ventilation modes with specific initial conditions. The inhalation proportion of droplet aerosols for air curtain was 0.016%, which was significantly lower than that for mixed ventilation (0.049%) and displacement ventilation (0.071%). The air curtain confined the transmission of droplet aerosols with the minimum ratios of inhalation, deposition, and suspension and is thus recommended to reduce the exposure risk.
近期新型冠状病毒肺炎（COVID-19）的爆发威胁到了公众健康。由于电梯轿厢环境相对封闭且通风较差，乘客存在呼吸道感染风险。然而，电梯轿厢内飞沫气溶胶的分布和扩散情况仍不清楚。本研究调查了在三种通风模式下源患者呼出的飞沫气溶胶的传播情况。通过计算流体动力学（CFD）模拟解析了经鼻腔呼吸和咳嗽产生的飞沫气溶胶。我们采用经过验证的重整化群（RNG）湍流模型来模拟流场，并采用拉格朗日方法来追踪飞沫气溶胶。此外，评估了通风模式对飞沫传播的影响。结果表明，在特定初始条件下的混合通风和置换通风模式下，飞沫气溶胶聚集在电梯轿厢内且难以排出。气幕通风模式下飞沫气溶胶的吸入比例为0.016%，显著低于混合通风（0.049%）和置换通风（0.071%）。气幕以最低的吸入、沉积和悬浮比例限制了飞沫气溶胶的传播，因此建议采用气幕通风以降低暴露风险。
