Laser-assisted visualization and measurement of corridor smoke spread

A new visualization technique using a laser sheet is introduced to reveal smoke spread in a corridor. Thermocouples are used to measure the speed of the ceiling jet front and vertical distribution of temperatures in the corridor. From the measurement results it is found that the formation of a smoke layer can be divided into two steps: before and after the impingement of the jet front on the end wall of the corridor. It is shown that the rate of smoke lowering is slowest in the vicinity of the end of the corridor before the impingement and it is fastest in the same area after the impingement. The oscillating behavior of smoke layer interface after the impingement is also demonstrated. (C) 1998 Elsevier Science Ltd. All rights reserved.