Numerical investigation on indoor aerosol dispersion due to natural ventilation with single-sided opening

¹ Graduate Student, Department of Architecture, Shinshu University, Nagano, Japan
² Associate Professor, Environmental Civil Engineering and Architecture, Nagoya University, Aichi, Japan
³ Professor, Department of Architecture, Tokyo University of Science, Tokyo, Japan
⁴ Assistant Professor, Department of Architecture, Tokyo University of Science, Tokyo, Japan

^* Corresponding author: 22w5029k@shinshu-u.ac.jp

Abstract

The purpose of this study is to evaluate the characteristics of ventilation runoff of particles. Using CFD analysis, the indoor space with the single-side opening model is filled with particles and passive scalar to provide differential temperature ventilation. The RANS and the LES analysis methods, as well as the size and the number of particles generated in a room, will be changed to compare the indoor concentration and ventilation rate trends. The particles are assumed to be water particles that do not evaporate. As the result with the turbulence models, the LES analysis tended to be closer to the passive scalar and theoretical behavior characteristics for small particles than the RANS analysis, because the diffusion of particles is also considered. As the result with the number of particles, the behavior characteristics of the LES analysis became closer to that of the passive scalar as the number of particles increased. As the result of the size of particles, in this model particles larger than 10 µm are deposited indoors by gravitational settling, increasing the percentage removed from the indoors. Therefore, it can be concluded that the risk of infection is reduced without ventilation for particles above 10 µm in this model.