Acoustic energy radiated by nonlinear spherical oscillations of strongly driven bubbles

Abstract

Based on the theory of F. Gilmore (Gilmore 1952 The growth or collapse of a spherical bubble in a viscous compressible liquid) for radial oscillations of a bubble in a compressible medium, the sound emission of bubbles in water driven by high-amplitude ultrasound is calculated. The model is augmented to include expressions for a variable polytropic exponent, hardcore and water vapour. Radiated acoustic energies are calculated within a quasi-acoustic approximation and also a shock wave model. Isoenergy lines are shown for driving frequencies of 23.5 kHz and 1 MHz. Together with calculations of stability against surface wave oscillations leading to fragmentation, the physically relevant parameter space for the bubble radii is found. Its upper limit is around 6 mm for the lower frequency driving and 1-3 mm for the higher. The radiated acoustic energy of a single bubble driven in the kilohertz range is calculated to be of the order of 100 nJ per driving period; a bubble driven in the megahertz range reaches two orders of magnitude less. The results for the first have applications in sonoluminescence research. Megahertz frequencies are widely used in wafer cleaning, where radiated sound may be implicated as responsible for the damage of nanometre-sized structures.

Early appearance of crystalline nanoparticles in pulsed laser ablation in liquids dynamics

“…48,49 The Gilmore equation incorporates water compressibility and condensation to reach a better agreement with bubble dynamics. [50][51][52] Nevertheless, we are mostly interested in the expanding bubble, where virtually no differences between the RP and Gilmore equations can be found with appropriate fitting parameters. 53 The particle mass as derived from the partial invariant of the large particles (20 to 80 nm) is presented in the bottom part of Fig.…”

Bubble dynamics in boiling histotripsy

“…To model the evaporation and condensation of vapour (i.e. the phase change between liquid and gas), (Holzfuss 2005(Holzfuss , 2010Hauke et al 2007;Kreider et al 2011), assumes the liquid-vapour interface is planar and takes the temperature distributions in the bubble and liquid as fixed (Holzfuss 2008). This model is generally applicable as an estimate of phase change below the critical temperature of the liquid (Kreider 2008).…”

On the governing fragmentation mechanism of primary intermetallics by induced cavitation

“…Implosion of cavitation bubbles and the resulting shock pressure field has been widely studied in water [24] , [25] , [26] , [27] , [28] , [29] , [30] . Cavitation bubbles are generated during the rarefaction phase of the incident ultrasonic wave, grow in size and rapidly collapse when they reach a critical resonance size during the compression cycle producing high-speed jets and local hydrodynamic impact pressures in the range of GPa [31] .…”