CFD Simulation of Bubble Growing Under a Downward Facing Surface
The heat removing of downward facing surface is an important issue in many areas, including nuclear safety, solar storage system and electronic cooling devices. Therefore, the characteristic and heat removal capability of downward facing boiling were investigated by many experiments in recent years. Among these studies, the thickness of bubble is considered as an important parameter. The increasing of bubble thickness will increase the thermal resistance of cooling process and reduce the cooling ability. In order to focus on the dynamics of bubble thickness, Das et al. injected air into sodium dodecyl sulphate (SDS) solution through a nozzle under the horizontal downward facing surface. The bubble will be formed by the air injection and kept under the horizontal plate. The diameter of nozzle, horizontal plate and SDS solution tank are 2 mm, 20 mm and 30 mm, respectively. The growing processing and the stable thickness of the bubble were recorded in the experiment. Basing on the conditions of Das's experiment, the appropriate computational fluid dynamics (CFD) simulation was conducted. The growing process and the stable thickness of bubble under difference contact angle are predicted by CFD in this study.