采用两套光偏转测试装置对不同表面张力液体中激光空泡脉动及溃灭特性进行了实验研究,获得了液体表面张力改变对固壁近旁空泡生长和溃灭过程的影响。结果表明,表面张力延缓了空泡的膨胀过程,加速了空泡的溃灭;表面张力对空泡溃灭的影响要强于对膨胀的影响;液体张力越大,空泡脉动周期越短,且空泡对应的最大泡半径越小而收缩所能达到的最小泡半径亦越小。此外,液体张力越大,射流所产生的瞬时冲击力越大,即表面张力加强了液体射流对固壁的空蚀作用。研究结果可为水下激光加工、激光医疗、空化空蚀相关流体力学的研究提供一定的理论和实验支持。
The growth and collapse of a cavitation bubble near a rigid boundary in liquids with different surface tensions was investigated by two sensitive fiber-optic sensors based on optical beam deflection. The experimental results show that the surface-tension forces slow down bubble growth progress, but speed up bubble collapse process. The influence of the surface tension on bubble expansion is stronger than that on collapse. Increasing surface-tension decreases the maximum and the minimum bubble radii and shortens the oscillation times. Furthermore, the larger the surface tension is, the stronger impact of the high pressure liquid jet will be. That is to say, cavitation erosion is reduced as decreasing the surface tension. These results help to better understand the cavitation erosion and optimize laser parameters in the fields of laser ophthalmology and underwater laser processing.