A model of laser‐induced bubble formation and collapse mechanism Free

It is well known that the high power laser can produce the breakdown of liquid [M. P. Felix et al., Appl. Phys. Lett. 19, 484 (1971)]. The bubble formation and the shock wave emission after the breakdown have been observed simultaneously [W. Lauterborn and E. J. Ebeling, Appl. Phys. Lett. 31, 663 (1977)]. Usually, the cavity concept that the bubble is empty has been employed as an initial condition for the study of bubble motion. In this study, the initial conditions of the bubble evolution due to laser irradiation, i.e., the bubble wall velocity and the pressure inside the bubble just after the bubble evolution, were obtained from the bubble formation model proposed by Kwak and Panton [J. Phys. D 18, 647 (1985)]. Subsequent bubble evolution were calculated numerically by using the Gilmore equation in a compressible region and by using the Rayleigh equation in an incompressible region. The elapsing time from the bubble formation to the first bubble collapse and the farfield pressure signal at the first bubble collapse are in good agreement with the experimental results [W. Lauterborn (pp. 3–12) and V. S. Teslenko (pp. 30–34), both in Cavitation and Inhomogeneities in Underwater Acoustics, edited by W. Lauterborn (Springer, New York, 1980)]. Also, calculation results showed that shock strength and the amplitude of the pressure wave at the first collapse are strongly dependent upon the initial bubble wall velocity.