Quantitative distribution of human exhaled particles in a ventilation room

Abstract

Respiratory viruses can be attached to human exhaled particles and spread from person to person through respiratory activities. The purpose of this study is to obtain the quantitative description formula of human exhaled particles in the ventilated room through amount number of numerical simulation calculations and regression statistical analysis of the simulated data. In this study, a combination of numerical simulation and laboratory experiments was used, and the results were tallied preferably. Bacillus subtilis was released as a release source to investigate the migration and distribution of bioaerosol. The results show that under the condition of high air supply velocity, due to the disturbance of human respiration and airflow, the diffusion velocity of exhaled particles was faster and the diffusion range is larger than that of low air supply velocity within the same time frame. No matter where the location of the manikin was in the room, the exhaled particles would spread to the whole room in at least 900 s. The method used in this study could be used to predict the distribution of human exhaled particles concentration in different indoor spaces, such as public transport and hospitals. These findings could provide valuable reference for the location of indoor air purifiers, which plays a guiding role in the construction of a healthy indoor environment.

A model to evaluate ozone distribution and reaction byproducts in aircraft cabin environments

“…Pressure discretization was based on PRESTO! (pressure staggering option) 34,35 . The computations were considered to have converged when the scaled velocity and continuity residuals approached 10 −3 and the energy residuals reached 10 −6 .…”

“…(pressure staggering option). 34,35 The computations were considered to have converged when the scaled velocity and continuity residuals approached 10 −3 and the energy residuals reached 10 −6 . The governing equations were solved using the SIMPLE algorithm in the commercial CFD software ANSYS FLUENT 2021 R1.…”

Quantitatively Visualizing Airborne Disease Transmission Risks of Different Exhalation Activities through CO2 Imaging

“…Accordingly, both the propagation distance and the propagation area mentioned in this study were discriminated by the identifiable airflow boundary, whereas the nuclei of exhaled droplets in the real environment may have the ability to propagate much further. 43 , 44 Among the propagation distances, the diagonal distance, which can be calculated from horizontal and vertical directions, refers to the maximum visible length in the direction of propagation along the exhaled airflow.…”

Estimating the restraint of SARS-CoV-2 spread using a conventional medical air-cleaning device: Based on an experiment in a typical dental clinical setting

“…The transmission of bioaerosols in the dental clinic was studied by both experimental research and numerical simulation, which is the most typical method to investigate bioaerosol concentrations ( Komperda et al, 2021 ; Liu et al, 2022 ; Polednik, 2021 ). A previous study reported that dental treatment causes a considerable increase in airborne bioaerosol concentrations in dental clinics, although the analyses were not comprehensive ( Dutil et al, 2008 ).…”