Axial temperature distribution in vertical jet fires.

The behaviour of vertical commercial propane jet fires (flame lengths of up to 8m) was studied experimentally. The temperatures along the jet fire centreline were measured using a set of thermocouples and the flame contour was determined from infra-red (IR) images. The results show that temperature increases from the bottom of the flame, reaches a maximum value and decreases again at the top zone. A second-degree polynomial expression describes fairly well the variation of temperature as a function of the position on the flame centreline. The temperature along the centreline was found to increase for Q values lower than 7MW and to decrease at higher values.