Scientists and engineers who wish to understand the earth’s subsurface are faced with a daunting challenge. Features of interest range from the microscale (centimeters) to the macroscale (hundreds of kilometers). It is unlikely that computational power limitations will ever allow modeling of this level of detail. Numerical upscaling is one technique intended to reduce this computational burden....

Campos, Legendre, and Sambuc [1] derived an acoustic-vortical wave equation for the study of acoustics within a sheared flow U0(y)ex over an acoustic lining with a constant cross flow V0ey through the lining. Unfortunately, their derivation makes inconsistent assumptions, and the resulting wave equation is therefore incorrect. This comment points out the error, and derives a corresponding equat...

The multi-chamber reactive silencers are widely used to reduce engine exhaust noise as well as blower intake and discharge noise. Davis et al. [1] developed a one-dimensional analytical approach, which assumes plane wave propagation in the axial direction in silencers, to predict the acoustic attenuation performance of double expansion chamber reactive silencers, and compared the predictions wi...

Abstract In the present study, ion-acoustic solitary wave solutions for Kadomtsev–Petviashvili (KP) equation, potential KP and Gardner equation are constructed. The nonlinear equations studying process of waves without collisions plasma having non-isothermal electrons cold ions. Two-dimensional (IASWs) in magnetized consisting We obtained same as dark bright, kink anti-kink solitons. physical p...

A study of 400 Hz sound focusing and ducting effects in a packet of curved nonlinear internal waves in shallow water is presented. Sound propagation roughly along the crests of the waves is simulated with a three-dimensional parabolic equation computational code, and the results are compared to measured propagation along fixed 3 and 6 km source/receiver paths. The measurements were made on the ...

the existing theory for wave propagation through a soil layer are not compatible with the real soil layers because in the theory the layers are flat and the sub-layers are parallel, while in real the soil layers are not flat and they may not be parallel. thus, wave propagations through a corrugated interface are so important. in this paper, a two-dimensional sh-wave propagation through a corrug...

In this work G'/G-expansion method has been employed to solve (2+1)-dimensional dispersive long wave equation. It is shown that G'/G-expansion method, with the help of symbolic computation, provides a very effective and powerful mathematical tool, for solving this equation.

The KPI equation is one of most well-known nonlinear evolution equations, which was first used to described two-dimensional shallow water wavs. Recently, it has found important applications in fluid mechanics, plasma ion acoustic waves, optics, and other fields. In the process studying these topics, very obtain exact solutions equation. this paper, a general Riccati treated as an auxiliary equa...

This report concerns the behavior, at large times, of solutions of two-dimensional wave equations in exterior regions. This behavior is related to low frequency calculations for the reduced wave equation. Both Dirichlet and Neumann boundary data are considered, and it is shown that there are differences in the two cases. The results also differ greatly from the corresponding ones in three dimen...

The linear and nonlinear theories of electron-acoustic waves (EAWs) are studied in a partially degenerate quantum plasma with two-temperature electrons stationary ions. initial equilibrium is assumed to be given by the Fermi–Dirac distribution at finite temperature. By employing multi-scale asymptotic expansion technique one-dimensional Wigner–Moyal Poisson equations, it shown that effects mult...