High-Frequency Multipulse, Plane-Wave Acoustic Contrast Imaging

Acoustic characterisation of ultrasound contrast agents at high frequency

High-frequency nonlinear acoustic beams and wave packets

Gaussian beams and wave packets are formally equivalent to high-frequency solutions of the linear wave equation with complex-valued phase functions. The theory of weakly nonlinear high-frequency waves is extended in this paper to allow for complex phase solutions. The procedure is similar to nonlinear geometrical optics and the nonlinearity causes the phase to vary, leading to the development o...

Approximation of High Frequency Acoustic Wave Surface Integrals

This paper is concerned with the efficient evaluation of some highly oscillatory surface integrals, arising from boundary integral methods for high frequency acoustic scattering in three dimensions. The performance of standard quadrature schemes deteriorates as the frequency of the incident wave increases. We present ideas for improving the evaluation of such highly oscillatory integrals. Intro...

Theory of High Frequency Acoustic Wave Scattering by Turbulent Flames

This paper describes an analysis of acoustic wave scattering by turbulent premixed flames with moving, convoluted fronts that have random and possibly fractal characteristics. Such interactions play a role in the characteristic unsteadiness observed in turbulent combustion processes. The problem is posed with an integral formulation of the wave equation and assumes that the smallest scales of f...

Capillary wave motion excited by high frequency surface acoustic waves

This paper presents a numerical and experimental study of capillary wave motion excited by high frequency surface acoustic waves SAWs . The objective of this study is to provide insight into the dynamic behavior of the fluid free surface and its dependence on the excitation amplitude. A two-dimensional numerical model that couples the motion of the piezoelectric substrate to a thin liquid layer...