scholarly journals Properties of axial surface waves along dielectrically coated conducting cylinders

2012 ◽  
Vol 10 ◽  
pp. 79-84 ◽  
Author(s):  
U. Siart ◽  
S. Adrian ◽  
T. Eibert
Keyword(s):  
Surface Waves ◽  
Power Distribution ◽  
Wave Fields ◽  
Cylinder Radius ◽  
Fundamental Properties ◽  
Cutoff Frequencies ◽  
Phase Constant ◽  
Hybrid Waves ◽  
Conducting Cylinders ◽  
Axial Surface

Abstract. In this paper the fundamental properties of surface waves along conducting cylinders with and without dielectric coating are investigated for cylinder diameters in the centimeter range and frequencies in the gigahertz range and higher. Analytical results for the phase constant and attenuation versus the cylinder radius are derived and cutoff frequencies of various TE, TM, and hybrid waves are computed. The radial power distribution is computed in order to investigate the spatial extent of the wave fields.

Fundamental properties of surface waves in lossless stratified structures

2010 ◽  
Vol 466 (2120) ◽  
pp. 2447-2469 ◽  
Author(s):  
Guido Valerio ◽  
David R. Jackson ◽  
Alessandro Galli
Keyword(s):  
Surface Waves ◽  
Dispersion Equation ◽  
High Frequency ◽  
Low Frequency ◽  
Layered Structures ◽  
Graphical Solution ◽  
Fundamental Properties ◽  
The Past ◽  
Permittivity And Permeability ◽  
Constitutive Parameters

This paper is focused on dispersive properties of lossless planar layered structures with media having positive constitutive parameters (permittivity and permeability), possibly uniaxially anisotropic. Some of these properties have been derived in the past with reference to specific simple layered structures, and are here established with more general proofs, valid for arbitrary layered structures with positive parameters. As a first step, a simple application of the Smith chart to the relevant dispersion equation is used to prove that evanescent (or plasmonic-type) waves cannot be supported by layers with positive parameters. The main part of the paper is then focused on a generalization of a common graphical solution of the dispersion equation, in order to derive some general properties about the behaviour of the wavenumbers of surface waves as a function of frequency. The wavenumbers normalized with respect to frequency are shown to be always increasing with frequency, and at high frequency they tend to the highest refractive index in the layers. Moreover, two surface waves with the same polarization cannot have the same wavenumber at a given frequency. The low-frequency behaviours are also briefly addressed. The results are derived by means of a suitable application of Foster’s theorem.

scholarly journals Statistical properties of nonlinear one-dimensional wave fields

2005 ◽  
Vol 12 (5) ◽  
pp. 671-689 ◽  
Author(s):  
D. Chalikov
Keyword(s):  
Surface Waves ◽  
Nonlinear Wave ◽  
High Accuracy ◽  
Statistical Properties ◽  
Statistical Characteristics ◽  
Small Scale ◽  
Sea Waves ◽  
Wave Fields ◽  
Linear Waves ◽  
Stokes Waves

Abstract. A numerical model for long-term simulation of gravity surface waves is described. The model is designed as a component of a coupled Wave Boundary Layer/Sea Waves model, for investigation of small-scale dynamic and thermodynamic interactions between the ocean and atmosphere. Statistical properties of nonlinear wave fields are investigated on a basis of direct hydrodynamical modeling of 1-D potential periodic surface waves. The method is based on a nonstationary conformal surface-following coordinate transformation; this approach reduces the principal equations of potential waves to two simple evolutionary equations for the elevation and the velocity potential on the surface. The numerical scheme is based on a Fourier transform method. High accuracy was confirmed by validation of the nonstationary model against known solutions, and by comparison between the results obtained with different resolutions in the horizontal. The scheme allows reproduction of the propagation of steep Stokes waves for thousands of periods with very high accuracy. The method here developed is applied to simulation of the evolution of wave fields with large number of modes for many periods of dominant waves. The statistical characteristics of nonlinear wave fields for waves of different steepness were investigated: spectra, curtosis and skewness, dispersion relation, life time. The prime result is that wave field may be presented as a superposition of linear waves is valid only for small amplitudes. It is shown as well, that nonlinear wave fields are rather a superposition of Stokes waves not linear waves. Potential flow, free surface, conformal mapping, numerical modeling of waves, gravity waves, Stokes waves, breaking waves, freak waves, wind-wave interaction.

Excitation of lower hybrid waves by electron beams in finite geometry plasmas. Part 2. Surface waves

1978 ◽  
Vol 19 (2) ◽  
pp. 295-299
Author(s):  
Réal R. J. Gagné ◽  
Magdi M. Shoucri
Keyword(s):  
Electron Beam ◽  
Surface Waves ◽  
Electron Beams ◽  
Low Frequency ◽  
Finite Geometry ◽  
Dispersion Relations ◽  
Lower Hybrid ◽  
Small Density ◽  
Hybrid Waves ◽  
Lower Hybrid Waves

The dispersion relations for the quasi-static lower hybrid surface waves are derived. Conditions for their existence and their linear excitation by a small density electron beam are discussed. Instabilities appearing in low-frequency surface waves are also discussed.

Electron energization in lunar magnetospheres

2010 ◽  
Vol 76 (6) ◽  
pp. 915-918 ◽  
Author(s):  
R. BINGHAM ◽  
R. BAMFORD ◽  
B. J. KELLETT ◽  
V. D. SHAPIRO
Keyword(s):  
Shock Wave ◽  
Solar Wind ◽  
Bow Shock ◽  
Lower Hybrid ◽  
Wave Fields ◽  
Resonant Interactions ◽  
Hybrid Waves ◽  
Lower Hybrid Waves ◽  
Turbulent Wave ◽  
Stream Instability

AbstractThe interaction of the solar wind with lunar surface magnetic fields produces a bow shock and a magnetosphere-like structure. In front of the shock wave energetic electrons up to keV energies are produced. This paper describes how resonant interactions between plasma turbulence in the form of lower-hybrid waves and electrons can result in field aligned electron acceleration. The turbulent wave fields close to the lower-hybrid resonant frequency are excited most probably by the modified two-stream instability, driven by the solar wind ions that are reflected and deflected by the low shock.

On the cutoff conditions and power distribution in fibres of arbitrary cross section

1991 ◽  
Vol 69 (5) ◽  
pp. 612-615 ◽  
Author(s):  
S. Bhattacharjee ◽  
V. J. Menon ◽  
K. K. Dey
Keyword(s):  
General Theory ◽  
Cross Section ◽  
Power Distribution ◽  
Arbitrary Cross Section ◽  
Relative Power ◽  
Small Eccentricity ◽  
The Core ◽  
Cutoff Frequencies ◽  
Power Content ◽  
Analytical Expressions

A recently developed general theory of propagation constants in weakly guiding, noncircular fibres is extended to derive simple, analytical expressions for the modal cutoff frequencies and relative power content of the core. The results are illustrated numerically for elliptic fibres of small eccentricity, and also interpreted physically.

scholarly journals Imaging Seismic Wave-Fields with AlpArray and Neighboring European Networks

2020 ◽  
Author(s):  
Marcel Tesch ◽  
Johannes Stampa ◽  
Thomas Meier ◽  
Edi Kissling ◽  
György Hetényi ◽  
...  
Keyword(s):  
Surface Waves ◽  
Wave Field ◽  
Seismic Wave ◽  
Time Window ◽  
Deep Structure ◽  
Body Wave ◽  
Broad Band ◽  
Wave Fields ◽  
Short Period ◽  
Spatio Temporal

Abstract. The modern-day coverage and availability of broad-band stations in the greater Alpine area offered by AlpArray, Swath-D and the European seismological networks allows for imaging seismic wave-fields at yet unprecedented resolution. In the AlpArray area and in Italy, the distance of any point to the nearest station is less than 30 km, resulting in an average inter-station distance of about 45 km. With a much denser deployment in a smaller region of the Alps (320 km in length and 140 km wide), the Swath-D network possesses an average inter-station distance of about 15 km. We provide single event seismogram sections, time slices of teleseismic and regional wave-fields, and wave-field animations to reveal both the resolution capabilities of this dense station distribution as well as the enormous spatio-temporal complexity of seismic wave propagation. The time slices and wave-field animations demonstrate the need for dense regional arrays of broad-band stations, such as provided by AlpArray and neighboring networks, to resolve properties of teleseismic wave-fields. Here we present the images of coherent arrivals of direct body and surface waves, multiple body wave reflections, and multi-orbit phases for teleseismic and regional events with moment magnitudes larger than 6 over a time window of at least 2:45 hours. Spatial observations of the wave-fields illustrate e.g. the decrease in horizontal wavelength from P to S to surface waves and the way in which they considerably deviate from plane waves, due to heterogeneous earth structures along the path from the source to the array and beneath the regional array itself. Tomographic imaging techniques for the deep structure beneath the regional array have to take this spatio-temporal variability into account and correct for it. The lateral resolution of the regional broad-band array is however dependent on station density, in this case limited to about 100 km. Only even denser station distributions like those provided by Swath-D suffice to recover wave-fields of short period body and surface waves.

Fundamental Properties of the Low Voltage Power Distribution Grid Used as a Data Channel

2000 ◽  
Vol 11 (3) ◽  
pp. 297-306 ◽  
Author(s):  
Klaus Dostert ◽  
Manfred Zimmermann ◽  
Torsten Waldeck ◽  
Michael Arzberger
Keyword(s):  
Power Distribution ◽  
Low Voltage ◽  
Distribution Grid ◽  
Data Channel ◽  
Fundamental Properties

Damping of surface waves in an incompressible liquid

1957 ◽  
Vol 2 (2) ◽  
pp. 172-184 ◽  
Author(s):  
K. M. Case ◽  
W. C. Parkinson
Keyword(s):  
Boundary Layer ◽  
Surface Waves ◽  
Viscous Dissipation ◽  
Laminar Boundary Layer ◽  
Small Amplitude ◽  
Incompressible Liquid ◽  
Experimental Results ◽  
Cylinder Radius ◽  
Theory And Experiment ◽  
Good Agreement

The damping of surface waves of small amplitude in liquid contained in cylinders has been calculated. Viscous dissipation in an assumed laminar boundary layer was taken to be the primary cause of damping. Experimental results were obtained for the logarithmic decrement as a function of the ratio of liquid height to cylinder radius for several water-filled cylinders. Theory and experiment were found to be in good agreement.

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