AVERAGE CENTERLINE TEMPERATURES OF A BUOYANT POOL FIRE OBTAINED BY IMAGE-PROCESSING OF VIDEO RECORDINGS

Images from a standard video camera are used to obtain an average centreline temperature distribution of simulated pool fires. By using a novel technique, characteristic length scales are extracted from the flame images. With this information and the use of empirical correlations, the mean centreline temperature distribution is obtained. The range of validity of this technique is determined by conducting experiments with a gas burner (250mm x 400mm). The heat release rate and Froude number are set so that the flames are characteristic of fire scenarios. Thermocouple measurements, along the flame centreline, are compared with the temperature distributions obtained from the video images. It was found that the video technique gives an accurate estimate of the mean centreline temperatures for different levels of confinement and heat release rates. There is no apparent colour or intensity limitation since good results were obtained for flames with dramatically different characteristics. Finally, the results obtained from the video recordings are also compared with previously reported experimental data and correlations with very good agreement, thus, confirming the possibilities of this technique in determining the characteristics of flames typical of building scale fires.