激光空泡特性实验与数值计算研究

Laser induced bubble characteristics with experimental and numerical methods

基于激光空泡内物质以水蒸气为主的特征,选择特定的Rayleigh-Plesset方程形式,确定激光空泡的动态泡壁位置,并考虑水中气体与激光空泡之间的质量扩散、水蒸气的凝结与蒸发、水的压缩性及热传导、声辐射、黏性、表面张力等因素.建立激光空泡的产生、照相和声压测量系统.通过数值计算与实验结果相结合的办法,使泡内压力的计算值与实验值之间相对误差控制在10%以内,揭示吸收的激光脉冲能量与激光空泡的半径、泡内压力和温度之间的对应关系,以及吸收的激光脉冲能量不变时半径、压力和温度的变化规律.旨在为激光空泡的相关研究提供一定的参考.

According to the characteristics that a laser induced bubble is filled with mostly water vapor and a little noncondensable gas,a specific Rayleigh-Plesset equation which was used to determine the position of the dynamic bubble wall and other concerned conditions were used. Mass diffusion between the bubble and the gases dissolved in surrounding water,compression of water,condensation and evaporation at the bubble wall,heat conduction,sound radiation,viscosity of water and surface tension were considered. A laser induced bubble producing,photographing and pressure measuring system was set up. Numerical and experimental method was used;the relative error of pressure inside bubble was under 10%. The relations were showed among the absorbed laser puergy,the pressure and the temperature in the bubble and the bubble radius.