An experimental study on jet diffusion flame shapes by means of image processing

摘要

An experimental study is performed to observe and record the dynamic behavior of jet diffusion flames from vertical circular nozzles. A real-time color image processing on slow-motion video recording is employed to investigate the effects of nozzle diameter and fuels on the flame morphology. Emphasis is placed on the determination of the flame liftoff height, L_h, and the liftoff flame-base width, B_W, based on the variations of RGB values of the flame. Methane and propane are used as fuel and three nozzles with the diameters of 1.25, 1.69 and 2.40 mm are tested. It is found from the study that (i) an effect of fuel on the flame liftoff height and the liftoff flame-base width appears, and (ii) L_h is directly proportional to B_W.