Acoustic energy radiated by nonlinear spherical oscillations of strongly driven bubbles

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 μm for the lower frequency driving and 1–3 μm 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.

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A shock wave model of unstable rocket combustors

AIAA Journal ◽

10.2514/3.2534 ◽

1964 ◽

Vol 2 (7) ◽

pp. 1285-1296 ◽

Cited By ~ 46

Author(s):

L. CROCCO ◽

W. A. SIRIGNANO

Keyword(s):

Shock Wave ◽

Wave Model ◽

Shock Wave Model

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Variability of GRB light curve: Shock wave model modification

Journal of Physics Conference Series ◽

10.1088/1742-6596/133/1/012030 ◽

2008 ◽

Vol 133 ◽

pp. 012030

Author(s):

Saša Simić ◽

Luka Č Popović

Keyword(s):

Shock Wave ◽

Light Curve ◽

Wave Model ◽

Model Modification ◽

Shock Wave Model

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Shock-wave model of the earthquake and Poincaré quantum theorem give an insight into the aftershock physics.

E3S Web of Conferences ◽

10.1051/e3sconf/20186203006 ◽

2018 ◽

Vol 62 ◽

pp. 03006

Author(s):

Vladimir Kuznetsov

Keyword(s):

Shock Wave ◽

Wave Model ◽

Particle Systems ◽

Many Body ◽

Initial State ◽

Recurrence Theorem ◽

Shock Wave Model ◽

Quantum Phenomena ◽

First Time ◽

Insight Into

A fundamentally new model of aftershocks evident from the shock-wave model of the earthquake and Poincaré Recurrence Theorem [H. Poincare, Acta Mathematica 13, 1 (1890)] is proposed here. The authors (Recurrences in an isolated quantum many-body system, Science 2018) argue that the theorem should be formulated as “Complex systems return almost exactly into their initial state”. For the first time, this recurrence theorem has been demonstrated with complex quantum multi-particle systems. Our shock-wave model of an earthquake proceeds from the quantum entanglement of protons in hydrogen bonds of lithosphere material. Clearly aftershocks are quantum phenomena which mechanism follows the recurrence theorem.

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Microbubble dynamics in a viscous compressible liquid near a rigid boundary

IMA Journal of Applied Mathematics ◽

10.1093/imamat/hxz009 ◽

2019 ◽

Vol 84 (4) ◽

pp. 696-711 ◽

Cited By ~ 1

Author(s):

Qianxi Wang ◽

WenKe Liu ◽

David M Leppinen ◽

A D Walmsley

Keyword(s):

Potential Flow ◽

Stokes Equations ◽

Bubble Surface ◽

Compressible Liquid ◽

Boundary Integral ◽

Boundary Integral Method ◽

Viscous Effects ◽

Rigid Boundary ◽

Viscous Potential Flow ◽

Viscous Compressible Liquid

Abstract This paper is concerned with microbubble dynamics in a viscous compressible liquid near a rigid boundary. The compressible effects are modelled using the weakly compressible theory of Wang & Blake (2010, Non-spherical bubble dynamics in a compressible liquid. Part 1. Travelling acoustic wave. J. Fluid Mech., 730, 245–272), since the Mach number associated is small. The viscous effects are approximated using the viscous potential flow theory of Joseph & Wang (2004, The dissipation approximation and viscous potential flow. J. Fluid Mech., 505, 365–377), because the flow field is characterized as being an irrotational flow in the bulk volume but with a thin viscous boundary layer at the bubble surface. Consequently, the phenomenon is modelled using the boundary integral method, in which the compressible and viscous effects are incorporated into the model through including corresponding additional terms in the far field condition and the dynamic boundary condition at the bubble surface, respectively. The numerical results are shown in good agreement with the Keller–Miksis equation, experiments and computations based on the Navier–Stokes equations. The bubble oscillation, topological transform, jet development and penetration through the bubble and the energy of the bubble system are simulated and analysed in terms of the compressible and viscous effects.

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Acoustic energy harvesting from vortex-induced tonal sound in a baffled pipe

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406211406017 ◽

2011 ◽

Vol 225 (8) ◽

pp. 1847-1850 ◽

Cited By ~ 3

Author(s):

R Hernandez ◽

S Jung ◽

K I Matveev

Keyword(s):

Acoustic Pressure ◽

Electrical Energy ◽

High Amplitude ◽

Acoustic Mode ◽

Acoustic Energy ◽

Electric Load ◽

Mean Flow ◽

Acoustic Resonators ◽

Acoustic Energy Harvesting ◽

Mean Flow Velocity

Energy of high-amplitude sound that often appears in acoustic resonators with mean flow can be harnessed and converted into electricity for powering sensors and other devices. In this study, tests were conducted in a simple setup consisting of a pipe with a pair of baffles and a piezoelement. Tonal sound, corresponding to the second acoustic mode of the resonator, was excited due to vortex shedding/impinging on baffles in the presence of mean flow. Generated sound energy was partially converted into electrical energy by a piezoelement. About 0.55 mW of electric power was produced on a resistive electric load at acoustic pressure amplitudes in the pipe about 170 Pa and mean flow velocity 2.6 m/s.

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