Large scale 3D particle tracking for the study of airborne transmission of pathogens in realistic class room settings

Abstract

In populated confined rooms the Lagrangian transport of small aerosol particles and their accumulation over time has been identified as the main pathway for indirect infections of persons by respiratory viruses, like Sars-CoV-2 or measles. In this project, we will further develop and apply 3D Lagrangian particle tracking and distributed temperature sensors in order to determine the volumetric transport of small aerosol particles in mixed turbulent convection under well-defined boundary conditions. Therefore, a ~70 m³ test room with optical access for a set of 8 emergent GMAX 65 Mpx streaming cameras and a large array of pulsed LEDs for the illumination of submillimeter HFSBs has been established at DLR Göttingen. A seminar room type configuration with 8 seated dummies at tables including a teacher and a mechanical lung have been choosen . The aim of these experiments is to quantify the time-scales for the distribution of potentially harmful viruses via airborne transport pathways and the accumulation of aerosol particles. Thus, we aim at providing a critical risk assessment for infection chains under various conditions and ventilation scenarios.The investigations specifically focus on dynamic situations and transient processes, like switching-on and -off of mitigation measures, e.g. window- or door- opening, operating air purifiers or fan ventilators, but we will as well involve a real moving person.