EXPERIMENTAL STUDY ON BUBBLE BURSTING AND DROPLET RELEASING CHARACTERISTICS UNDER DIFFERENT LIQUID PHASE CONDITIONS

The phenomenon that bubble bursts at the water surface and results in droplets production is one of the source of radioactive aerosol release, when the gas goes through the aerosol pool. Based on this, a high-speed photographic visualization experimental device was used to visualize the bubble bursting process at liquid surface under different conditions. Experimental studies show that: the bursting process of the bubbles with 7mm-28mm in diameter is a Single point rupture process. The process includes bubble rising, bubble cap draining, punctured point appearing, the liquid film rolling-up which forms the liquid ring, droplets emission as liquid ring breaks. The different punctured position changes the process of bubble bursting and the distribution of the droplets, thus the location of punctured position were divided into different area, which mainly locates at the foot of the bubble cap. Furthermore, the change of liquid phase conditions will affects the location of the punctured position, the number and the sizes of droplets. In the experiments, as temperature of the liquid phase changes from 16 degrees C to 60 degrees C, the process of drainage of bubble cap is shortened,and the probability of punctured position at the bottom increases. When punctured position is the same position, the number of droplets decreased and the diameter of droplet increased as temperature was increasing.