Jet entrainment effect on fire-induced flow in isothermal model applied to reduced-scale tunnel

Based on the entrainment rate of isothermal jet, an application method of the isothermal model in tunnel fire was presented through the more reasonable estimation of total smoke flow rate and its density at jet exit. Acetone LIF measurement was performed to identify the entrainment of ambient air qualitatively, and the entrainment constants were provided with the results of a previous study of which jet velocity corresponded to that of this study. The entrainment effect was more remarkable for the smaller fire, because the normalized axial distance to ceiling was increased with decreasing the fire size. These results suggested that the present model considering the jet entrainment might enhance the previous isothermal model in tunnel fire.