单孔鼓泡影响因素的数值模拟与试验

NUMERICAL SIMULATIONS AND EXPERIMENTS STUDY OF AFFECT FACTORS FOR AIR BUBBLING IN SINGLE HOLE

采用Fluent软件中的VOF模型,模拟低气速下,不同参数对空气在水中单孔鼓泡过程的影响,并与试验结果进行比较,研究发现:筛孔直径及进孔气速越大,生成的气泡直径越大,气泡脱离孔口的时间越短;表面张力系数增大,气泡直径随之增大,气泡脱离孔口的时间变长。因此,增加水温、降低水的表面张力系数,有利于强化气水相间的加湿传质。

Air bubbling humidification is an efficient humidifying method used in solar desalination. Study of the main factors affecting the formation of air bubbling in humidifier is helpful to improve humidifying effect. In this paper,VOF model in Fluent software was used to simulate the affects of different parameters on the single-hole bubbling process at low air velocity. It ＇s compared the simulated results with the experimental ones, the conclusions are that the lager the sieve hole and the large the air velocity passing through a sieve were,the shorter the time required for bubble leaving from a sieve and the larger the bubble diameter was; as the water surface tension coefficient increased,the bubble diameter and the time required for bubble leaving from a sieve would be increased. Thus,increasing the water temperature in humidifier can help to reduce the surface tension coefficient of water,which can strengthen mass transfer between air and water in humidification.