Assessing Particle Concentration in the Breathing Zone of a Receptor Mannequin in an Indoor Environment

Abstract

Abstract This study examined the distribution and dispersion of respiratory droplets in a ventilated office space containing two mannequins with a partition between them. It was assumed that one of the mannequins was speaking and emitting respiratory droplets., The transition k-kl-ω turbulence model was employed to analyze the airflow pattern and the dispersion of droplets in the presence of the partition. The ANSYS-Fluent code was used to simulate the airflow conditions in the room. The Lagrangian particle tracking method was used to evaluate the droplet velocity and trajectories in the room. The Discrete Random Walk (DRW) model was used to simulate the effects of turbulence fluctuations on particle dispersion. The airflow conditions for different ventilation flow rates and dispersion of droplets of different sizes emitted by the speaking mannequin were evaluated. In addition, the concentration of droplets of different sizes near the receptor mannequin was evaluated. Furthermore, the distribution of droplets of varying sizes close to the receptor mannequin was evaluated. The droplet concentrations were evaluated using the two-way coupling technique implemented through ANSYS-Fluent code and a MATLAB Code using the Lagrangian particle tracking approach. The concentration results obtained from the Lagrangian approach are compared with those predicted by the enhanced diffusion model.