Study on inhalation region by means of CFD analysis and experiment

Computational fluid dynamics (CFD) analysis using a low Reynolds number k-ε model was performed to examine the inhalation region of a human body in a stagnant environment. To account for the influence of the three-dimensional form of the human body, a model that replicated the actual forms of a real human body was used. CFD analysis was applied first to a room model with an occupant. The inhalation region under steady-state conditions was examined with the assumption of steady inhalation. Subsequently, an unsteady breathing model was introduced and the respiration area was analyzed. The variation of the air-velocity distribution, the influence of the exhaustion on the inhalation was examined, and the inhalation region under unsteady-state conditions was also analyzed in detail. In this study, the inhalation region of an experimental thermal manikin was also examined by a tracer-gas experiment using a high-response flame ionized detector (FID). The thermal manikin was assumed to perform steady inhalation in the experiment. Results of simulation can be considered to agree well with the experimental results, and the CFD method using a human body with a complex shape is shown to be effective in studying the inhalation region.