The influence of human walking on the flow and airborne transmission in a six-bed isolation room: Tracer gas simulation

摘要

By performing unsteady CFD simulations using RNG – model and dynamic mesh technique, this paper investigates how the walking motion of health care worker (HCW) influences gaseous dispersion in a six-bed isolation room with nine downward supplies and six ceiling-level or floor-level exhausts. The flow near and behind HCW is easily affected by HCW motion. The flow disturbance induced by HCW walking with swinging arms and legs is a mixing process. The walking HCW displaces air in front of it and carries air in the wake forwardly, meanwhile pressure difference drives air from two lateral sides into the wake. HCW motion (0–5.4 s) indeed induces a little gaseous dispersion, but the residual flow disturbance after HCW stops (5.4 s–25.4 s) induces more gaseous agent spread and it requires more than 30–60 s to approximately recover to the initial state after HCW stops.