Spreading of SARS-CoV-2-laden aerosol particles in closed patient rooms

该项目调查了携带SARS-CoV-2病毒的呼吸道气溶胶飞沫在有和没有大容量空调（HVAC）系统的封闭病房中的空气传播和传播情况。这是基于这样一个假设，即病房内的气流场结构对气溶胶和病毒的传播有很强的影响。具体而言，将研究雾化液滴中的病毒载量如何与COVID-19患者口腔液样本中的病毒载量相关，以及这些相关性如何受到室内气候条件的影响，特别是空气流场结构、湿度和空气交换率、与患者的距离和行为（呼吸、说话、歌唱，但不咳嗽或打喷嚏）。采用大尺度、长时间的数值模拟方法，对带有病毒颗粒的气溶胶液滴的分散两相流动和病房内的湍流气流进行了模拟。在选定的空气流场监测点对气溶胶液滴和病毒颗粒进行评估。将数值数据与患者研究的相应信息进行比较，以确定病毒颗粒在空气中传播的重要相关性。

The project investigates the airborne transport and spread of respiratory aerosol droplets loaded with SARS-CoV-2 viruses in closed patient rooms with and without high-volume air conditioning (HVAC) system. It is based on the hypothesis, that the structure of the air flow field in a patient room has a strong impact on the spread of aerosols and viruses. In detail, it will be examined, how the viral load in the aerosolized droplets correlates with the viral load in oral fluid samples from COVID-19 patients and how these correlations are influenced by the room climatic conditions, in particular the air flow field structure, humidity and the air exchange rate, the distance from and the behavior of the patients (breathing, speaking, singing, but not coughing or sneezing).Large-scale, long-term numerical simulations of the dispersed two-phase flow of aerosol droplets seeded with virus particles and the turbulent air flow in the patient room are performed. The aerosol droplets and virus particles are evaluated at selected monitoring points in the air flow field. Numerical data is compared with corresponding information from a patient study in order to identify important correlations for the airborne transport of virus particles.