构建了激光空泡测量实验平台,使用脉冲激光聚焦击穿水介质产生激光空泡,由水听器对激光空泡溃灭辐射声信号进行接收,利用充气泵对高压水箱内的气压进行精确控制。通过仿真计算和实验对不同环境压强下的激光空泡特征和其溃灭时辐射声信号的峰值变化特性进行了研究。结果表明:当环境压强处在0.1~0.7 MPa范围内变化时,随着环境压强的增大,激光空泡首次脉动周期和空泡最大半径逐渐减小,两者的变化速率逐渐减小。空泡溃灭时辐射声信号的峰值声压在0.1~0.4 MPa内逐渐增大,在0.4~0.7 MPa内逐渐减小,且增大速率大于减小速率。
The experimental system for research on laser-induced bubbles in different surrounding pressures was built. Bubbles were produced by pulsed laser focusing into water. A hydrophone was used to receive the acoustic signals produced by laser-induced bubble collapse. The pressure inside the tank was accurately controlled by an air pump. Characteristics of laser-induced bubbles and peak pressure of acoustic signals produced by laser-induced bubble collapse in different surrounding pressures were investigated through simulation and experiment. The results show that the movement period and maximum radius of laser-induced bubbles decrease as the surrounding pressure increases from 0.1 MPa to 0.7 MPa gradually. The peak pressure of acoustic signals produced by laser-induced bubble collapse increases as surrounding pressure increases between 0.1-0.4 MPa, and that decreases as surrounding pressure increases between 0.4-0.7 MPa, the change speed of the former is larger than that of the latter.