The generation of surface waves over a sloping beach by an oscillating line-source. I. The general solution

1974 ◽  
Vol 76 (3) ◽  
pp. 545-554 ◽  
Author(s):  
Clare A. N. Morris
Keyword(s):  
General Solution ◽  
Integral Representation ◽  
Surface Waves ◽  
Line Source ◽  
Wave Train ◽  
Wave Generation ◽  
Outgoing Wave ◽  
Arbitrary Angle ◽  
Laplace Integral Representation ◽  
Sloping Beach

AbstractThe problem of wave generation by a line source of sinusoidally varying strength situated in water above a beach of arbitrary angle α(0 < α ≤ π) is solved by the use of a Laplace-integral representation of the solution. It is shown that a solution can be constructed which is regular at the shoreline and gives an outgoing wave-train at infinity.

The generation of surface waves over a sloping beach by an oscillating line source

1976 ◽  
Vol 79 (3) ◽  
pp. 573-585 ◽  
Author(s):  
Clare A. N. Morris
Keyword(s):  
Free Surface ◽  
Surface Waves ◽  
Line Source ◽  
Short Wave ◽  
Long Waves ◽  
Edge Waves ◽  
Wave Regime ◽  
Wave Solutions ◽  
Sloping Beach

AbstractA line source whose strength varies sinusoidally with time and also with the co-ordinate measured along its length is situated parallel to the shoreline of a beach of angle ¼π0. Both long-and short-wave solutions are found. It is shown that for certain positions of the source, long waves are not radiated to infinity, while in the short-wave regime, the solutions take the form of edge-waves, with resonances occurring at certain wavenumbers. Computations of the free-surface contours are presented for a range of wavenumbers.

The generation of surface waves over a sloping beach by an oscillating line-source. II. The existence of wave-free source positions

1974 ◽  
Vol 76 (3) ◽  
pp. 555-562 ◽  
Author(s):  
Clare A. N. Morris
Keyword(s):  
Surface Waves ◽  
Line Source ◽  
Sloping Beach ◽  
The Waves

AbstractAn expression is obtained for the amplitude of the waves radiated to infinity by a line source of sinusoidally-varying strength situated in water over a beach of angle α (0 < α ≤ π). It is shown that, for certain positions of the source, this amplitude is zero. Equations for the loci of these positions, and approximations to their solutions in particular cases, are derived.

Long wave generation on a sloping beach

1972 ◽  
Vol 51 (3) ◽  
pp. 449-461 ◽  
Author(s):  
E. O. Tuck And ◽  
Li-San Hwang
Keyword(s):  
Wave Equation ◽  
General Solution ◽  
Linear Theory ◽  
Ground Motion ◽  
Large Amplitude ◽  
Wave Generation ◽  
Long Wave ◽  
Time Histories ◽  
Near Shore ◽  
Sloping Beach

A general solution of the linear long-wave equation is obtained for arbitrary ground motion on a uniformly sloping beach. Numerical results are presented for specific shapes and time histories of ground motion. Near-shore large amplitude waves are also investigated using non-linear theory.

scholarly journals Suppression of Wind Ripples and Microwave Backscattering Due to Turbulence Generated by Breaking Surface Waves

2020 ◽  
Vol 12 (21) ◽  
pp. 3618
Author(s):  
Stanislav Ermakov ◽  
Vladimir Dobrokhotov ◽  
Irina Sergievskaya ◽  
Ivan Kapustin
Keyword(s):  
Remote Sensing ◽  
Surface Waves ◽  
Wave Breaking ◽  
Wave Train ◽  
Wind Waves ◽  
Breaking Waves ◽  
Doppler Spectrum ◽  
Strong Wave ◽  
Wave Maker ◽  
Radar Backscattering

The role of wave breaking in microwave backscattering from the sea surface is a problem of great importance for the development of theories and methods on ocean remote sensing, in particular for oil spill remote sensing. Recently it has been shown that microwave radar return is determined by both Bragg and non-Bragg (non-polarized) scattering mechanisms and some evidence has been given that the latter is associated with wave breaking, in particular, with strong breaking such as spilling or plunging. However, our understanding of mechanisms of the action of strong wave breaking on small-scale wind waves (ripples) and thus on the radar return is still insufficient. In this paper an effect of suppression of radar backscattering after strong wave breaking has been revealed experimentally and has been attributed to the wind ripple suppression due to turbulence generated by strong wave breaking. The experiments were carried out in a wind wave tank where a frequency modulated wave train of intense meter-decimeter-scale surface waves was generated by a mechanical wave maker. The wave train was compressed according to the gravity wave dispersion relation (“dispersive focusing”) into a short-wave packet at a given distance from the wave maker. Strong wave breaking with wave crest overturning (spilling) occurred for one or two highest waves in the packet. Short decimeter-centimeter-scale wind waves were generated at gentle winds, simultaneously with the long breaking waves. A Ka-band scatterometer was used to study microwave backscattering from the surface waves in the tank. The scatterometer looking at the area of wave breaking was mounted over the tank at a height of about 1 m above the mean water level, the incidence angle of the microwave radiation was about 50 degrees. It has been obtained that the radar return in the presence of short wind waves is characterized by the radar Doppler spectrum with a peak roughly centered in the vicinity of Bragg wave frequencies. The radar return was strongly enhanced in a wide frequency range of the radar Doppler spectrum when a packet of long breaking waves arrived at the area irradiated by the radar. After the passage of breaking waves, the radar return strongly dropped and then slowly recovered to the initial level. Measurements of velocities in the upper water layer have confirmed that the attenuation of radar backscattering after wave breaking is due to suppression of short wind waves by turbulence generated in the breaking zone. A physical analysis of the effect has been presented.

Diffraction by a perfectly conducting wedge in an anisotropic plasma

1965 ◽  
Vol 61 (3) ◽  
pp. 767-776 ◽  
Author(s):  
T. R. Faulkner
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Wave ◽  
Difference Equation ◽  
Integral Representation ◽  
Surface Waves ◽  
Uniform Magnetic Field ◽  
Anisotropic Plasma ◽  
Contour Integral ◽  
Anisotropic Dielectric

SummaryThe problem considered is the diffraction of an electromagnetic wave by a perfectly conducting wedge embedded in a plasma on which a uniform magnetic field is impressed. The plasma is assumed to behave as an anisotropic dielectric and the problem is reduced, by employing a contour integral representation for the solution, to solving a difference equation. Surface waves are found to be excited on the wedge and expressions are given for their amplitudes.

Vertex generated waves outside metallic wedges

1961 ◽  
Vol 57 (2) ◽  
pp. 393-400 ◽  
Author(s):  
W. E. Williams ◽  
L. Rosenhead
Keyword(s):  
Exact Solution ◽  
Difference Equation ◽  
Boundary Value Problem ◽  
Surface Impedance ◽  
Line Source ◽  
Complete Agreement ◽  
Magnetic Line ◽  
Arbitrary Angle ◽  
Surface Reactance ◽  
The Waves

ABSTRACTA study is made of the waves generated by a magnetic line source placed at the vertex of a wedge of high conductivity and arbitrary angle. The boundary-value problem is reduced to the solution of a difference equation and an exact solution obtained. The method is also applied to the case of dielectric coated wedges where the surface reactance and resistance are arbitrary, and the propagation of surface waves along such surfaces is considered briefly. The forms of the solution for large and small values of the surface impedance are obtained and show complete agreement with the known results available for a right-angled wedge and a plane.

On the sound field generated by membrane surface waves on a wedge-shaped boundary

1987 ◽  
Vol 411 (1840) ◽  
pp. 239-250 ◽  
Keyword(s):  
Exact Solution ◽  
Surface Wave ◽  
Surface Waves ◽  
Wave Amplitude ◽  
Membrane Surface ◽  
Sound Field ◽  
Acute Angle ◽  
Rigid Surface ◽  
Arbitrary Angle ◽  
Method Of Solution

A semi-infinite membrane, joined to a rigid surface at an arbitrary angle, supports incident unattenuated surface waves. A compressible fluid is contained within the two semi-infinite boundaries and the resultant reflected surface-wave amplitude and the scattered acoustic field is sought. A method of solution is presented for wedge angles(2 p + 1) π/2 q , p and q integers, and the exact solution is obtained for an acute angle of ¼π.

Sign in / Sign up

Export Citation Format

Share Document