Laser-induced breakout and detonation waves in droplets II Model

Breaking the Rayleigh-Plateau Instability Limit Using Thermocavitation Within a Droplet

“…It is important to mention that the vapor bubble is attached to the glass surface at all times, taking a hemispherical shape regardless of the power and location of the laser focal point, in contrast to pulsed-laser cavitation. In pulsed-laser cavitation the bubble is created wherever the focal point is and its shape depends on the distance from the solid-liquid boundary to the center of the bubble (Phillip and Lauterborn, 1998;Carls and Brock, 1991;Zheng et al, 1991;Robert et al, 2007;Heijnen et al, 2009;Thoroddsen et al, 2009;Eickmans et al, 1987;Hsieh et al, 1987). The bubble takes a hemispherical shape.…”

“…On the other hand, optical thermocavitation within a water droplet provides an alternative technique to produce liquid columns with delayed instability onset on demand. Until now, the principal mechanism for generation of cavitation bubbles within droplets has been the use of short-pulsed lasers (Carls and Brock, 1991;Zheng et al, 1991;Robert et al, 2007;Heijnen et al, 2009;Eickmans et al, 1987;Hsieh et al, 1987), where bubbles are generated by liquid optical breakdown when the laser beam is focused into a small spot. Thoroddsen et al (2009) used a pulsed Nd:YAG laser with pulse duration of 7 ns and maximum fluency of ∼42 J/cm 2 per pulse.…”

Controllable direction of liquid jets generated by thermocavitation within a droplet

“…Other techniques involve the use of short laser pulses [12][13][14][15][16][19][20][21][22] or a spark discharge [23] to create cavitation bubbles within a liquid, droplets, or thin films to produce liquid jets or spray. Among the techniques that use short laser pulses we can mention the laser-induced forward transfer (LIFT) technique [24][25][26][27][28].…”