scholarly journals Wave Radiation by A Submerged Ring Plate in Water of Finite Depth

2019 ◽  
Vol 33 (6) ◽  
pp. 660-672
Author(s):  
Pei-wen Cong ◽  
Ying-yi Liu ◽  
Ying Gou ◽  
Bin Teng
2000 ◽  
Vol 423 ◽  
pp. 155-173 ◽  
Author(s):  
J. R. CADBY ◽  
C. M. LINTON

We consider, using linear water-wave theory, three-dimensional problems concerning the interaction of waves with structures in a fluid which contains a layer of finite depth bounded above by a free surface and below by an infinite layer of fluid of greater density. For such a situation time-harmonic waves can propagate with two different wavenumbers K and k. In a single-layer fluid there are a number of reciprocity relations that exist connecting the various hydrodynamic quantities that arise, and these relations are systematically extended to the two-fluid case. The particular problems of wave radiation and scattering by a submerged sphere in either the upper or lower layer are then solved using multipole expansions.


1996 ◽  
Vol 40 (03) ◽  
pp. 224-234
Author(s):  
Ömer Gören

A vertical circular cylinder which is in periodic oscillatory motion with small amplitudes in finite depth is considered. The usual assumptions necessary for the potential flow stand valid in the present study. A classical perturbation procedure is employed to solve the nonlinear problem through the second-order. According to the solution method presented, the fluid domain is separated into interior and exterior regions in which boundary-value problems (BVP) are decomposed into two BVPs each having one nonhomogeneous boundary condition. A nonhomogeneous second-order free-surface condition is treated by means of a modified form of Weber's integral theorem. Eigenfunction expansions are used for homogeneous solutions. Thus, to conclude the solution, the exterior and interior solutions are then matched on the common boundary. Numerical results are given for a heaving vertical circular cylinder. Wave field analysis around a vertical cylinder shows that the second-order wave pattern is typically dominated by the second-order wave number related to the second-order dispersion relation. The procedure also satisfies the conditions at infinity through the second-order.


Author(s):  
Chih-Yu Kuo ◽  
Ruey-Lin Chern ◽  
Chien-Cheng Change

The three dimensional wave scattering of an oblique wave incident on a flanged circular compact pore of finite depth is solved analytically by the method of matched asymptotic expansion. We assume smallness of the product of the incident wave number and the pore radius and divide the scattering field into an inner region and an outer radiation region. For the wave system, the physical variables, e.g. sound pressure, electric/magnetic fields, satisfy the Laplace equation in the inner region. For the circular shaped pores, they can be solved by the method developed by Fabrikant. Then via the matching processes, the wave radiation in the outer field is determined. The theory is developed first for sound wave scattering. Both rigid and pressure-release boundary conditions are investigated. For a pore with a finite depth, the leading radiation terms for both conditions are at the same order of magnitude. They contain one monopole and one dipole for the former and one dipole for the latter. Quadrupoles and an octupole are found in the next higher order. Subsequently, the theory is applied to the electromagnetic wave scattering. The problems are formulated based on the duality property of the source-free Maxwell equations. A multipole expansion for the scattering wave similar to the acoustic counterpart is obtained. A few residue multipoles arising from the higher order inner region are found. The leading dipoles and their orientation are demonstrated.


2006 ◽  
Vol 36 (7) ◽  
pp. 1403-1419 ◽  
Author(s):  
Jerome A. Smith

Abstract The energy, momentum, and mass-flux exchanges between surface waves and underlying Eulerian mean flows are considered, and terms in addition to the classical wave “radiation stress” are identified. The formulation is made in terms of the vertically integrated flow. The various terms are identified with other analyses and interpreted in terms of physical mechanisms, permitting reasonable estimates of the associated depth dependencies. One term is identified with the integrated “CL vortex force” implemented, for example, in simulations of Langmuir circulation. However, as illustrated with a simple example of steady refraction across a shear zone, other terms of the same order can significantly alter the results. The classic example of long waves forced by short-wave groups is also revisited. In this case, an apparent singularity arising in shallow water is countered by finite-amplitude dispersion corrections, these being formally of the same order as the forced long-wave response, and becoming significant or dominant as shallow water is approached.


2000 ◽  
Author(s):  
Ian R. Young ◽  
Michael L. Banner ◽  
Mark M. Donelan
Keyword(s):  

2020 ◽  
Vol 9 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Shumin Du ◽  
Huaiyin Chen ◽  
Ruoyu Hong

AbstractWith the rapid development of electronics and information technology, electronics and electrical equipment have been widely used in our daily lives. The living environment is full of electromagnetic waves of various frequencies and energy. Electromagnetic wave radiation has evolved into a new type of environmental pollution that has been listed by the WHO (World Health Organization) as the fourth largest source of environmental pollution after water, atmosphere, and noise. Studies have shown that when electromagnetic wave radiation is too much, it can cause neurological disorders. And electromagnetic interference will cause the abnormal operation of medical equipment, precision instruments and other equipment, and therefore cause incalculable consequences. Therefore, electromagnetic protection has become a hot issue of concern to the social and scientific circles.


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