doi:10.3850/978-981-08-7724-8_03-06

ABSTRACT

The objective of this work is to investigate how the inflow, burning and outflow develop in a corridor open to one end having a fire at the closed or open end. The situation of a corridor fire having a fire source at the close end is a situation similar to a tunnel having a fire source at the centre of the tunnel without ventilation. A gaseous burner is used to produce the fire at a prescribed fuel flow (and heat release) rate in a long corridor of aspect ratio up to 6:1 having a rectangular cross section and varying door like dimensions at the opening. Gas temperatures using thermocouple trees, heat fluxes in the corridor and its facade, flame heights of emerging flames and total heat release rates are measured as the fuel flow rate increases gradually (nearly linearly) to a preset maximum value. For over-ventilated conditions the flames remain near the source fire at the closed end of the corridor. Unexpectedly, it was established for under ventilated conditions that the inflow of air is not affected by the aspect ratio of the corridor or the location of the burner in the corridor and that the vertical distribution of gas temperatures inside the enclosure is nearly uniform with height everywhere. Moreover, as the conditions changed from overventilated to underventilated, the flames migrated in a ghostly manner from the closed end to the open end of the corridor as soon as underventilated conditions were established. The speed of migration of the flames from the back to the front has also been inferred from the thermocouple tree measurements. Finally, implications of the present results for tunnel fires are also discussed.

Keywords: Enclosure fires, Corridor and tunnel like enclosure.

© 2011 CPD Unit, University of Leeds