Temperature stratification in tunnels

An investigation of previously established correlations between gas temperature distribution and smoke stratification in mines has been carried out for tunnel applications. The investigated correlations are based on excess gas temperature ratios and Froude number scaling. This paper describes a comparison between two large scale tests carried out in a road tunnel and two well defined model scale tests. In each of the tests, a longitudinal flow was maintained. The temperature data obtained at different locations and different heights have been used for the comparison. A good correspondence between the experimental data and the correlations has been found when the gas temperature data were used. However, the correspondence between the previously established correlation of gas temperature stratification and Froude number, was not reliable. It is postulated that the main reason for this may be the way the experiments were carried out. New correlations between the temperature stratification and the Froude number are also explored.

► A good correspondence between the experimental data and the correlations has been found when the gas temperature data were used.
► The correspondence between the previously established correlation of gas temperature stratification and Froude number, was not reliable.
► It is postulated that the main reason for this may be the way the experiments were carried out.
► Finally, new correlations between the temperature stratification and the Froude number were explored and recommended.