中文摘要：

超空化燃油射流使得喷雾中部分燃油分裂液滴内含有空化气泡；空化气泡的生长及溃灭对液滴的分裂与雾化具有重要影响。基于VOF方法首次对超空化条件下燃油液滴内空化气泡的生长及溃灭过程进行了数值模拟。通过研究发现，单液滴内空化气泡的生长过程可以按控制机理划分为表面张力控制阶段、综合竞争阶段和惯性力控制阶段；在第I阶段，空泡的生长主要受表面张力的控制作用，惯性力对空泡生长的促进作用及黏性力对空泡生长的抑制作用可以忽略；在第II阶段，空泡的生长受表面张力、惯性力及黏性力三者的综合作用，空泡的生长速率是促进空泡生长的惯性力和抑制空泡生长的表面张力及黏性力相互竞争、共同作用的结果；在第III阶段，空泡的生长主要受惯性力的控制作用，抑制空泡生长的表面张力及黏性力的作用基本可以忽略。单液滴内空化气泡的溃灭过程由多个溃灭阶段和反弹阶段构成，类似于有阻尼弹簧振子的振动过程；根据每个溃灭周期结束时空泡半径随时间的变化历程，可以将空泡的溃灭分为快速溃灭期、缓慢溃灭期以及稳定期；溃灭初期空泡溃灭压力的变化非常剧烈，但空泡溃灭体积的变化则要相对平缓得多；空泡反弹压力随时间的变化与空泡反弹体积随时间的变化基本对应。

英文摘要：

Cavitation bubbles always exist in the diesel jet leaving the nozzle and in the diesel droplets breaking up from the jet as a result of supercavitation of the diesel within the injection nozzle, and it can increase the instability of jet and droplets in part due to the two-phase mixture, while the mechanism of this effect is still unclear. Growth and collapse of spherically symmetric bubble within the diesel droplet has been then simulated numerically based on the volume of fluid （VOF） method. The numerical results show that the process of bubble growth is divided into three stages, including surface tension controlled domain, comprehensive competition controlled domain with the surface tension, the inertial force and the viscous force, and inertial force controlled domain. In addition, the bubble collapse within a droplet consists of multiple collapse and rebound stages, similar to the vibration process of a damping spring oscillator. According to the variation of bubble radius with time at the end of each cycle, the process of bubble collapse can be divided into fast, slow＆nbsp;and stable stages.