2020.11.02

Prediction and Countermeasures for Infection by Virus Contaminated Droplet in Indoor Environment #2

Research and Development by

Tsubokura Makoto, RIKEN Center for Computational Science / Kobe University

Corresponding Research Area

Indoor airflow simulation and visualization of droplets, which are necessary for improving the COVID-19 Infection Prevention Guidelines for each industrial sector


3. RA1: Air flow simulation - Dispersion of droplet and aerosol when loud voice is emitted

■Prediction of short-range droplet and aerosol dispersion when a loud voice is emitted (Left image: 3 seconds after emission; Right image: 23 seconds after emission)

Assuming that the singing is performed within 1.5 meters in front of listeners, listeners are exposed to droplets larger than 10 microns in diameter. Therefore, it is necessary to take measures against distance. On the other hand, since micro droplets spread over several meters, it is necessary to take measures to dilute the concentration by thorough ventilation.

3. RA1: Air flow simulation - Dispersion of droplet and aerosol in concert venues

■Risk assessment and countermeasures for droplet and aerosol infection in concert venues

■Performance evaluation of mechanical ventilation in the concert hall and prediction of short-range droplet and aerosol dispersion near the audience

Courtesy of Kobe University and Kajima, in cooperation with Riken and Kawasaki City

Hall was filled with virus-contaminated aerosol (red), and cleaning by outside air ventilation (blue) was predicted. Heat generation from 2000 audience and lights is also considered.

By appropriately operating the mechanical ventilation installed in the hall, the hall is almost purified in about 10 minutes. However, some areas, such as the side of the stage and the corner of the hall, are poorly ventilated. In addition to the thoroughness of the mechanical ventilation, the combined use of circulators, etc. should be carried out in order not to stagnate the air.

3. RA1: Air flow simulation - Dispersion of droplet and aerosol in taxi

■Risk assessment and countermeasures for droplet and aerosol infection in a taxi

■Evaluation of ventilation by air conditioning and window opening and countermeasures, evaluation of short-distance droplet and aerosol dispersion prediction and countermeasures

Courtesy of RIKEN and Kobe University, in cooperation with Toyohashi University of Technology, Kyoto Institute of Technology and Toyota Motor Corporation

Quantitative evaluation of ventilation promotion effect and risk reduction effect by air conditioner ON/OFF, existence of external ventilation, window opening, etc., and further risk reduction effect by partition will be examined, and the data which can contribute to establishment of guideline for infection risk reduction in the taxi will be provided.