Numerical simulation on the generation of ultrasound and formation of water fog in the ultrasonic gas atomizer.

The water spraying itself is a dynamic course, and it is affected not only by structural style of ultrasonic gas atomizer and compressed air pressure, but also by movement of compressed air flow and so on in the atomizer. Here, the main principle of fine droplet formation in the ultrasonic gas atomizer is that the liquid sheet is disrupted into droplets by the energy of the high velocity air. If the ultrasonic energy is supplied, finer droplets with high sphericity and uniform size distribution can be achieved. But it is difficult to measure the droplet sizes. An ingenious method of droplet measurement was attempted by capturing the droplets on a filter paper and there are subjected to image analysis to obtain the droplet sizes. However, droplet measurement is complicated and the correctness of the droplet sizes is not high. Also advantage of all of the device newly designed is not defined until the experimental measurement are advanced after they are manufactured. As development of an interpretative program, droplet measurement through the numerical simulation was attempted. This paper deals with the water atomization of ultrasonic gas atomizer by numerical simulation with CFD software-ANSYS Fluent. In this paper, generation of ultrasound is decided in the ultrasonic gas atomizer with resonance chamber and ultrasound characters (frequency, pressure level, power level) are decided. These results are proved through the comparison with experiment. The results indicate that ultrasonic gas atomizer is effective to apply to the industrial field such as dust cleaning process. Rational structure parameter and operating parameter are studied in next issue.