Dbouk Talib, Drikakis Dimitris
University of Nicosia, Nicosia CY-2417, Cyprus.
Phys Fluids (1994). 2021 Jan 1;33(1):011905. doi: 10.1063/5.0038180. Epub 2021 Jan 26.
The impact of air ventilation systems on airborne virus transmission (AVT), and aerosols in general, in confined spaces is not yet understood. The recent pandemic has made it crucial to understand the limitations of ventilation systems regarding AVT. We consider an elevator as a prototypical example of a confined space and show how ventilation designs alone, regardless of cooling or heating, contribute to AVT. Air circulation effects are investigated through multiphase computational fluid dynamics, and the performance of an air purifier in an elevator for reducing AVT is assessed. We have investigated three different flow scenarios regarding the position and operation of inlets and outlets in the elevator and a fourth scenario that includes the operation of the air purifier. The position of the inlets and outlets significantly influences the flow circulation and droplet dispersion. An air purifier does not eliminate airborne transmission. The droplet dispersion is reduced when a pair of an inlet and an outlet is implemented. The overall practical conclusion is that the placement and design of the air purifier and ventilation systems significantly affect the droplet dispersion and AVT. Thus, engineering designs of such systems must take into account the flow dynamics in the confined space the systems will be installed.
空气通风系统对密闭空间内空气传播病毒（AVT）以及一般气溶胶的影响尚不清楚。最近的疫情使了解通风系统在AVT方面的局限性变得至关重要。我们将电梯视为密闭空间的典型示例，并展示仅通风设计（无论制冷或制热）如何促成AVT。通过多相计算流体动力学研究空气循环效应，并评估电梯中空气净化器减少AVT的性能。我们研究了电梯中入口和出口位置及运行的三种不同流动场景，以及包括空气净化器运行的第四种场景。入口和出口的位置显著影响气流循环和液滴扩散。空气净化器并不能消除空气传播。当设置一对入口和出口时，液滴扩散会减少。总体实际结论是，空气净化器和通风系统的布置与设计会显著影响液滴扩散和AVT。因此，此类系统的工程设计必须考虑系统将要安装的密闭空间内的流动动力学。
