The Effect of Reynolds Number on the Ventilation Efficiency in a Wind Tunnel

The present work is concerned with the effect of the ventilation intensity on the worker exposure in a tunnel when the worker is facing the downstream direction and a gaseous contaminant is released in an arm length of his reach. A three-dimensional model of a manikin which was used in the experiments was created in order to study the effect of the mean inlet velocity which can be characterized by the Reynolds number based on the equivalent diameter of the head of the manikin. For this study, turbulent flow was assumed to enter the ventilation tunnel and exit at the other end from an exhaust duct. The scalar transport method was employed to determine the ethanol vapor concentration field. The results with the low_Re RNG turbulence model are compared to the ones with the RNG turbulence model. The results with the RNG k-ε turbulence model seem to agree better with the experimental data at higher Reynolds numbers. At lower Reynolds numbers there are significant differences between experiments and predictions.