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 cent reline temperature distribution of simulated pool fires. By using a no vel technique, characteristic length scales are extracted from the fla me 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 nu mber are set so that the flames are characteristic of fire scenarios. Thermocouple measurements, along the flame centreline, are compared wi th the temperature distributions obtained from the video images. It wa s found that the video technique gives an accurate estimate of the mea n centreline temperatures for different levels of confinement and heat release rates. There is no apparent colour or intensity limitation si nce good results were obtained for flames with dramatically different characteristics. Finally, the results obtained from the video recordin gs are also compared with previously reported experimental data and co rrelations with very good agreement, thus, confirming the possibilitie s of this technique in determining the characteristics of flames typic al of building scale fires.