Experimental Study on the Diffusion Flame Using Liquid Ethanol as Fuel in Mini-Scale

At Present, the study of mini-scale motor is a very hot topic. The diffusion flame of liquid fuel in mini-scale is influenced by many factors, which should be studied further. In present experiments, three ceramic tubes were used as burners. The inner diameters of these ceramic tubes are 1.0mm, 0.6mm, and 0.4mm respectively. The combustion flame of liquid ethanol was visualized by high-accuracy camera, and the temperature field of the flame was measured by IR camera. And the effect of buoyancy on the flame was analyzed qualitatively. The measured images of the flame show that the whole flame is composed of gas area, diffusion area and reaction area. Experimental results show that there is a linear relationship between the flame height and the flow rate of liquid ethanol. The flame non-dimensional height is nearly directly proportional to Reynolds number. The critical non-dimensional flame heights are nearly the same when quench extinguishing appears for different burners with different inner diameters. Buoyancy causes flame elongated in the direction of height.