Instability and breakup of cavitation bubbles within diesel drops

作     者：吕明 宁智 阎凯 付娟 孙春华 

作者机构：College of Mechanical and Electrical Engineering Beijing Jiaotong University 

出 版 物：《Chinese Journal of Chemical Engineering》 (中国化学工程学报（英文版）)

年 卷 期：2015年第23卷第1期

页      面：262-267页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：Supported by the National Natural Science Foundation of China(51276011) the National High Technology Research and Development Program of China(2013AA065303) Beijing Municipal Natural Science Foundation of China(3132016) the Opening Foundation of State Key Laboratory of Engines(K2013-3) 

主　　题：Stability Diesel droplet Cavitation bubble Secondary breakup 

摘      要：A modified mathematical model is used to study the effects of various forces on the stability of cavitation bubbles within a diesel droplet. The principal finding of the work is that viscous forces of fluids stabilize the cavitation bubble, while inertial force destabilizes the cavitation bubble. The droplet viscosity plays a dominant role on the stability of cavitation bubbles compared with that of air and bubble. Bubble–droplet radius ratio is a key factor to control the bubble stability, especially in the high radius ratio range. Internal hydrodynamic and surface tension forces are found to stabilize the cavitation bubble, while bubble stability has little relationship with the external hydrodynamic force. Inertia makes bubble breakup easily, however, the breakup time is only slightly changed when bubble growth speed reaches a certain value(50 m·s-1). In contrast, viscous force makes bubble hard to break. With the increasing initial bubble–droplet radius ratio, the bubble growth rate increases, the bubble breakup radius decreases, and the bubble breakup time becomes shorter.