Large wave number vortices in time–periodic flows

1998 ◽  
Vol 454 (1978) ◽  
pp. 2689-2722
Author(s):  
P. J. Blennerhassett ◽  
J. P. Denier ◽  
A. P. Bssom
Keyword(s):  
Wave Number ◽  
Large Wave ◽  
Periodic Flows ◽  
Large Wave Number ◽  
Time Periodic

scholarly journals Causality and stability conditions of a conformal charged fluid

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Farid Taghinavaz
Keyword(s):  
Chemical Potential ◽  
Second Law Of Thermodynamics ◽  
Dense Medium ◽  
Wave Number ◽  
Second Law ◽  
Stability Conditions ◽  
Charged Fluid ◽  
Large Wave ◽  
The Stability ◽  
Large Wave Number

Abstract In this paper, I study the conditions imposed on a normal charged fluid so that the causality and stability criteria hold for this fluid. I adopt the newly developed General Frame (GF) notion in the relativistic hydrodynamics framework which states that hydrodynamic frames have to be fixed after applying the stability and causality conditions. To do this, I take a charged conformal matter in the flat and 3 + 1 dimension to analyze better these conditions. The causality condition is applied by looking to the asymptotic velocity of sound hydro modes at the large wave number limit and stability conditions are imposed by looking to the imaginary parts of hydro modes as well as the Routh-Hurwitz criteria. By fixing some of the transports, the suitable spaces for other ones are derived. I observe that in a dense medium having a finite U(1) charge with chemical potential μ0, negative values for transports appear and the second law of thermodynamics has not ruled out the existence of such values. Sign of scalar transports are not limited by any constraints and just a combination of vector transports is limited by the second law of thermodynamic. Also numerically it is proved that the most favorable region for transports $$ {\tilde{\upgamma}}_{1,2}, $$ γ ˜ 1 , 2 , coefficients of the dissipative terms of the current, is of negative values.

LOW-ENERGY ELECTRON HOLOGRAMS: PROPERTIES AND METHOD OF INVERSION

1997 ◽  
Vol 04 (03) ◽  
pp. 459-467 ◽  
Author(s):  
S. Y. TONG ◽  
T. P. CHU ◽  
HUASHENG WU ◽  
H. HUANG
Keyword(s):  
Electron Diffraction ◽  
Integral Transformation ◽  
Low Energy ◽  
Energy Electron ◽  
Wave Number ◽  
Large Wave ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Diffraction Patterns ◽  
Large Wave Number

We examine the differences between low-energy electron-diffraction patterns (holograms) and optical holograms. We show that electron-diffraction patterns in solids are not analogous to optical holograms because of strong dynamical factors. We also show that low-energy electron holograms can be inverted by a large-wave-number small-angle integral transformation. The grid sizes in wave number and angular spaces used in the transformation are derived.

Stationary gravity waves on non-uniform free streams: jet-like streams

1975 ◽  
Vol 77 (2) ◽  
pp. 415-438 ◽  
Author(s):  
D. H. Peregrine ◽  
Ronald Smith
Keyword(s):  
Free Surface ◽  
Gravity Waves ◽  
Small Amplitude ◽  
Wave Number ◽  
Explicit Solutions ◽  
Stationary Waves ◽  
Two Dimensional ◽  
Large Wave ◽  
Surface Gravity Waves ◽  
Large Wave Number

AbstractThe basic state considered in this paper is a parallel flow of a jet-like character with the centre of the jet being at or near a free surface which is horizontal. Stationary surface gravity waves may exist on such a flow, and a number of examples are looked at for small amplitude waves. Explicit solutions are given for ‘top-hat’ profile jets and for two-dimensional flows. Asymptotic solutions are developed for stationary waves of large wave-number.

Asymptotic Stability of an Eikonal Transformation Based ADI Method for the Paraxial Helmholtz Equation at High Wave Numbers

2012 ◽  
Vol 12 (4) ◽  
pp. 1275-1292 ◽  
Author(s):  
Qin Sheng ◽  
Hai-Wei Sun
Keyword(s):  
Helmholtz Equation ◽  
Numerical Stability ◽  
Splitting Method ◽  
Computational Procedure ◽  
Matrix Analysis ◽  
Wave Number ◽  
Large Wave ◽  
High Wave ◽  
Wave Numbers ◽  
Large Wave Number

AbstractThis paper concerns the numerical stability of an eikonal transformation based splitting method which is highly effective and efficient for the numerical solution of paraxial Helmholtz equation with a large wave number. Rigorous matrix analysis is conducted in investigations and the oscillation-free computational procedure is proven to be stable in an asymptotic sense. Simulated examples are given to illustrate the conclusion.

LARGE WAVE NUMBER FEATURES OF FORM FACTORS FOR PHASE TRANSITION KINETICS

1988 ◽  
Vol 02 (07) ◽  
pp. 861-867 ◽  
Author(s):  
Y. OONO ◽  
S. PURI
Keyword(s):  
Numerical Experiments ◽  
Finite Thickness ◽  
Form Factors ◽  
Wave Number ◽  
Large Wave ◽  
Sum Rule ◽  
Drastic Effect ◽  
Phase Transition Kinetics ◽  
Phase Ordering ◽  
Large Wave Number

Porod’s law and Tomita’s sum rule are two universal features expected for form factors of systems undergoing phase ordering processes, but have never been conclusively observed in numerical experiments. We demonstrate the drastic effect of finite thickness of interfaces on these asymptotic laws. Our results strongly suggest that the form factor obtained by Ohta, Jasnow and Kawasaki is asymptotically accurate, if not exact.

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