Results 271 to 280 of about 1,108,586 (322)

Geometrical Crystal Acoustics

1984
Publisher Summary This chapter discusses geometrical crystal acoustics. Acceleration waves in an inhomogeneous and anisotropic two-dimensional elastic solid are studied using compatibility relations generalized from those of T. Y. Thomas. Ray directions and an integral expression for decay are obtained in the case of differentiable inhomogeneity of ...
R.S.D. Thomas, H. Cohen
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Modelling the Propagation of a Weak Fast-Mode MHD Shock Wave near a 2D Magnetic Null Point Using Nonlinear Geometrical Acoustics

, 2012
We present the results of analytical modelling of fast-mode magnetohydrodynamic wave propagation near a 2D magnetic null point. We consider both a linear wave and a weak shock and analyse their behaviour in cold and warm plasmas.
A. Afanasyev, A. Uralov
semanticscholar   +1 more source

Acoustic Geometric and Acoustic Cyclotron Resonances in Gallium

Physical Review B, 1972
Acoustic geometric and acoustic cyclotron resonances in high-purity single crystals of gallium were investigated at 1.3 \ifmmode^\circ\else\textdegree\fi{}K and in the normal geometry where the magnetic field is perpendicular to the wave vector of the ultrasonic waves.
C. Alquié, J. Lewiner
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Coherence propagation and geometric acoustics

The Journal of the Acoustical Society of America, 1986
In this work, the method of propagating the mutual coherence function through a deterministic environment using geometric acoustic Green’s functions is shown. It is also demonstrated how WKB Green’s functions for the acoustic field result in the locally quadratic approximation for the coherence function. Next, it is shown that an exact channel function
David H. Berman, John J. McCoy
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Geometrical Acoustics. WKB Approximation

1990
The importance of geometrical acoustics, or the ray method, in studying sound fields in inhomogeneous media can hardly be exaggerated. Regardless of the physical nature of the waves considered, this approach is also often referred to as geometrical optics or the eikonal approximation.
Leonid M. Brekhovskikh, Oleg A. Godin
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Geometrical Acoustic Propagation with Frequency Dependence

The Journal of the Acoustical Society of America, 1968
One characteristic of geometrical-acoustic solutions is their frequency independence. Geometrical acoustics stems from the solution of the eikonal equation, which is a form of the wave equation in the limit of infinite frequency. Since the effects of the medium and the boundary conditions on the acoustic fields are definitely frequency dependent, it is
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Geometrical Acoustics at Microwave Frequencies

1972
Abstract : The purpose of this investigation is to study focusing and deflection of microwave acoustic bulk wave and surface wave beams in inhomogeneous anisotropic solids and to evaluate potential device application of these effects. Initially, the emphasis was on strictly geometrical effects and on inhomogeneities induced by means of magnetic and ...
S. Farnow, B. A. Auld
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Direct application of the diffusers’ reflection patterns in geometrical acoustics simulations

Applied Acoustics, 2022
Wojciech Binek, A. Pilch, T. Kamisiński
semanticscholar   +1 more source

Inhomogeneous absorption and geometric acoustics

The Journal of the Acoustical Society of America, 1998
The conventional formulation of geometric acoustics in the presence of inhomogeneous (spatially varying) absorption is examined. This formulation is found to fail under conditions of multipath propagation, because interference between ray paths is not taken into account when the absorptive losses are calculated.
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Dependence of acoustic levitation capabilities on geometric parameters

Physical Review E, 2002
A two-cylinder model incorporating boundary element method simulations is developed, which builds up the relationship between the levitation capabilities and the geometric parameters of a single-axis acoustic levitator with reference to wavelength. This model proves to be successful in predicting resonant modes of the acoustic field and explaining ...
W J, Xie, B, Wei
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