黏性液体中激光空泡脉动特性的理论和实验研究

通过自行研制的光偏转测试系统对黏性液体中激光空泡脉动特性进行了实验，获得了激光等离子体空泡前两次脉动全过程，从而判定了空泡在脉动过程中对应的最大和最小泡半径；并将不同黏性系数下空泡脉动结果与基于空泡溃灭理论的计算结果进行了对比.结果表明：液体黏性对空泡生存周期、空泡半径，以及泡壁的运动速度等均有影响.受液体黏性影响，空泡膨胀或收缩过程明显变缓，其相应的生存周期也越长.这一研究结果不仅可促进空化研究的深入，也可为合理利用空化现象提供参考. 关键词： 激光泡 脉动特性 黏性 光纤传感器

The collapse and rebound of laser-induced cavitation bubble in viscous fluid

The oscillation property of a laser-induced cavitation bubble in a viscous fluid is investigated by a sensitive fiber-optic sensor based on optical beam deflection. The temporal and spatial evolutions of the bubble wall during the expansion and collapse are traced according to sequential waveforms induced by the bubble oscillation. Both the maximum and minimum bubble radii at each oscillation cycle are determined by experiment. Further, in combination with the theoretical analysis and numerical calculation, the variation of the maximum and minimum radii during oscillation and life-time of the bubble in different viscous fluids is obtained. The experimental results indicate that the liquid viscosity has an obvious influence on the bubble oscillation; larger viscosity makes the bubble contract more slowly, and the corresponding minimum radius and the bubble life-time become larger and longer, while the maximum radius is smaller.