The COVID-19 infection has emerged as a disruptive pandemic at worldwide level. The study of the mechanism of contagion is one of the greatest challenges before a mass vaccination campaign that would protect populations. The study can support the development of knowledge and tools to develop possible strategies for containing its spread in future events. The saliva droplet aerosol expelled during breathing or coughing is the main cause for the propagation of the SARS-Cov-2. In this work, a URANS CFD approach was used to simulate the dispersion from the mouth of these particles in closed environments. The air conditioning system was considered. The conditions were varied to determine their impact on the diffusion of the aerosol. Lagrangian and Eulerian numerical approaches were used to model the coughing and the breathing events. These were validated with the puff theory, numerical and experimental results. A realistic case of a meeting room with two persons was simulated. Different characteristics of the expulsed aerosols and different ventilation system configurations were considered to demonstrate how these simulations can support management strategies for indoor occupation. Finally, the effect of the protective mask was introduced to quantify its beneficial effects to support safe indoor occupation.

COVID-19 感染已成为全球范围内的破坏性流行病。在保护人群的大规模疫苗接种运动之前，对传染机制的研究是最大的挑战之一。该研究可以支持知识和工具的发展，以制定可能的策略，以遏制其在未来事件中的传播。呼吸或咳嗽时排出的唾液飞沫气溶胶是 SARS-Cov-2 传播的主要原因。在这项工作中，URANS CFD 方法用于模拟封闭环境中这些颗粒从口中的扩散。考虑了空调系统。改变条件以确定它们对气溶胶扩散的影响。拉格朗日和欧拉数值方法用于模拟咳嗽和呼吸事件。这些都得到了膨化理论、数值和实验结果的验证。模拟了一个有两个人的会议室的真实案例。考虑到排出的气溶胶的不同特征和不同的通风系统配置，以证明这些模拟如何支持室内占用的管理策略。最后，介绍了防护面罩的作用，以量化其有益效果，以支持安全的室内职业。