The impedance problem for the propagative Helmholtz equation in the interior multiply connected domain is studied in2 and3 dimensions by a special modification of a boundary integral equation method. Additional boundaries are introduced inside interior parts of the boundary of the domain. The solution...
the acoustic impedance of the wave, equals, as for plane waves, the characteristic impedance of the medium Z0 = ρ0c0. At large distance a spherical wave behaves locally like a plane wave. For a spherical diverging harmonic wave of angular frequency ω with time dependence e‒ιwt (...
rayl- unit of acoustic impedance. Rayleigh equation- a ratio of red to green required by each observer to match spectral yellow. Synonym(s):Rayleigh test Rayleigh test- Synonym(s):Rayleigh equation Medical Eponyms © Farlex 2012 A colour equation representing a match of yellow (usually 589 nm...
A new method of profile inversion for acoustic waves propagating in a medium with spherical inhomogeneity based on the Schwinger variational method is presented. The wave equation of interest is transformed into a Schrodinger equation, so that the Born approximation and the new method could also be...
In this paper a numerical method for determining the modal properties of a structure in contact with an acoustic medium is explored. The acoustic field is reformulated as an integral equation. The application of collocation transforms the problem into one of solving a non-linear eigenvalue problem...
The Multidimensional Wave Equation with Generalized Acoustic Boundary Conditions I: Strong Stability 来自 学术范 喜欢 0 阅读量: 68 作者:Z Abbas,S Nicaise 摘要: This work attempts to establish OpenFOAM [1] 1 as a suitable software platform for computing su-personic flows over cavities with the ...
In this paper, we consider the Dirichlet and impedance boundary value problems for the Helmholtz equation in a non-locally perturbed half-plane. These boundary value problems arise in a study of time-harmonic acoustic scattering of an incident field by a sound-soft, infinite rough surface where ...
By considering their limits of applicability the equivalence of the two approaches is established. There is, however, no a priori reason for neglecting Fermi-liquid effects which, through the existence of zero sound modes, are essential for understanding direct measurements of the acoustic impedance....
2‐D Waveform inversion in the Laplace domain for acoustic‐elastic coupled media Although waveform inversion has been intensively studied in an effort to properly delineate the Earth's structures since the early 1980s, most of the time-... HS Bae,C Shin,Dong㎎oo Min,... - Seg Technical ...
The acoustic wave equation states that the pressure satisfies the equation: (62)c2∇2p=∂2p∂t2 For illustrative purposes, consider the one-dimensional case in which the waves are traveling in the x direction. The equation satisfied in this case is (63)c2∂2p∂x2=∂2p∂t2 The ...