Index of content:
Volume 116, Issue 2, August 2004
- ULTRASONICS, QUANTUM ACOUSTICS, AND PHYSICAL EFFECTS OF SOUND 
116(2004); http://dx.doi.org/10.1121/1.1771618View Description Hide Description
The acoustic field of a homogeneous and isotropic cylinder generated by a laser point source in either ablation or thermoelastic regime is obtained theoretically. A three-dimensional Fourier transform is used to calculate the acoustic displacement at the cylinder surface. Experimental waveforms were measured and analyzed for both regimes. Theoretical normal displacements under either regime are calculated and compared to the experimental signals for aluminum cylinders. Very good agreements are observed in the arrival time, shape, and relative amplitude (i) of the cylindrical Rayleigh waves with different round trips, and (ii) of the various longitudinal and transverse bulk waves propagating through the cylinder or reflected at the free circular surface.
116(2004); http://dx.doi.org/10.1121/1.1768255View Description Hide Description
Using the Lagrangian formalism, coupled equations are derived that describe radial and translational motions of an arbitrary bubble in a three-dimensional cluster subject to an ultrasound field. The obtained equations incorporate the nonlinear coupling of the volume and the translational modes of bubbles as well as interactions between all bubbles in the cluster up to terms of third order in the inverse separation distances. Solving these equations for each bubble in a multibubble structure, consisting of N bubbles with arbitrary spatial arrangement, the collective dynamics of this structure can be simulated. The potentialities of the proposed model in simulating the bubble dynamics in strong ultrasound fields are illustrated by numerical examples.