Investigation of the ventilation system inlet location effect on particle motion in a room using MRT-LBM

In this work Multi-Relaxation Time Lattice Boltzmann Method (MRT-LBM) is used to investigate the effect of the inlet air position on particle motion in a room. The sub-scale modeled room is one-tenth the scale of a full-size room with dimensions of 0.914 m×0.305 m×0.457 m and two different positions (ceiling and floor) are considered for the inlet air with dimension of 0.101m×0.101m. Large Eddy Simulation (LES) with Standard Smagorinsky model is utilized to simulate the turbulent indoor airflow. Particles with 1 and 10 micrometer sizes are selected for investigation of particle dispersion and deposition on the walls of the room. Number of deposited particles and those exiting the room show that when the inlet air is on the floor, the number of particles leaving through the exhaust register with bigger size (10µm) is more than the case for ceiling position. For smaller particles (1 µm) there is no significant difference between the floor and ceiling position of the inlet air for particles leaving the room thought the exhaust register. Results show that the gravity force significantly affect the particle deposition, as the number of deposited 10 µm particles on the floor are about 100 times that of the deposited 1 µm particles when the inlet air position is at ceiling.