Nonlinear Effects in the Propagation of Large-Amplitude Alfvén Waves in a Laboratory Plasma

1968 ◽  
Vol 11 (3) ◽  
pp. 557 ◽  
Author(s):  
R. C. Cross
Keyword(s):  
Large Amplitude ◽  
Nonlinear Effects ◽  
Laboratory Plasma

Whipping Response of Vessels With Large Amplitude Motions

2006 ◽  
Author(s):  
Nuno Fonseca ◽  
Eduardo Antunes ◽  
Carlos Guedes Soares
Keyword(s):  
Time Domain ◽  
Large Amplitude ◽  
Nonlinear Effects ◽  
Regular Waves ◽  
Structural Dynamic ◽  
Highly Nonlinear ◽  
Large Amplitude Motions ◽  
Structural Dynamic Characteristics ◽  
The Time Domain ◽  
Equations Of Motions

The paper presents a time domain method to calculate the ship responses in heavy weather, including the global structural loads due to whipping. Since large amplitude waves induce nonlinear ship responses, and in particular highly nonlinear vertical structural loads, the equations of motions and structural loads are solved in the time domain. The “partially nonlinear” time domain seakeeping program accounts for the most important nonlinear effects. Slamming forces are given by the contribution of two components: an initial impact due to bottom slamming and flare slamming due to the variation of momentum of the added mass. The hull vibratory response is calculated applying the modal analysis together with direct integration of the differential equations in the time domain. The structural dynamic characteristics of the hull are modeled by a finite element representation of a Timoshenko beam accounting for the shear deformation and rotary inertia. The calculation procedure is applied to a frigate advancing in regular waves. The contribution of whipping loads to the vertical bending moments on the ship structure is assessed by comparing this response with and without the hull vibration.

scholarly journals Resurrecting dead-water phenomenon

2011 ◽  
Vol 18 (2) ◽  
pp. 193-208 ◽  
Author(s):  
M. J. Mercier ◽  
R. Vasseur ◽  
T. Dauxois
Keyword(s):  
Internal Waves ◽  
Large Amplitude ◽  
Experimental Studies ◽  
Nonlinear Effects ◽  
Stratified Fluid ◽  
Nonlinear Internal Waves ◽  
Induced Drag ◽  
Wave Induced ◽  
Dead Water ◽  
Peculiar Phenomenon

Abstract. We revisit experimental studies performed by Ekman on dead-water (Ekman, 1904) using modern techniques in order to present new insights on this peculiar phenomenon. We extend its description to more general situations such as a three-layer fluid or a linearly stratified fluid in presence of a pycnocline, showing the robustness of dead-water phenomenon. We observe large amplitude nonlinear internal waves which are coupled to the boat dynamics, and we emphasize that the modeling of the wave-induced drag requires more analysis, taking into account nonlinear effects. Dedicated to Fridtjöf Nansen born 150 yr ago (10 October 1861).

Characteristics of large-amplitude alfv n waves in a laboratory plasma

1967 ◽  
Vol 9 (1) ◽  
pp. 43-52 ◽  
Author(s):  
I G Brown ◽  
C N Watson-Munro
Keyword(s):  
Large Amplitude ◽  
Laboratory Plasma

Characteristics of large-amplitude Alfv n waves in a laboratory plasma.

1967 ◽  
Vol 9 (4) ◽  
pp. 510-510
Author(s):  
I G Brown ◽  
C N Watson-Munro
Keyword(s):  
Large Amplitude ◽  
Laboratory Plasma

scholarly journals Effect of Roof Impacts on Coupling Between Wave Response and Sloshing in Tanks of LNG-Carriers

2008 ◽  
Author(s):  
Bernard Molin ◽  
Fabien Remy ◽  
Alain Ledoux ◽  
Nicolas Ruiz
Keyword(s):  
Potential Flow ◽  
Large Amplitude ◽  
Flow Model ◽  
Nonlinear Effects ◽  
Free Surfaces ◽  
Irregular Wave ◽  
Experimental Campaign ◽  
Wave Response ◽  
Potential Flow Model ◽  
Good Agreement

An experimental campaign is reported on the wave response of a rectangular barge supporting two rectangular tanks partly filled with water. Flat and chamfered tank roofs are successively tested, at varying heights above the free surfaces inside the tanks. The tests are carried out in irregular wave systems coming from abeam. The measured barge roll and sloshing motions in the tanks are compared with numerical results from a linearized potential flow model. Good agreement is reported in mild seastates. Nonlinear effects, associated with large amplitude sloshing motion and/or roof impacts, are investigated.

Large amplitude lower-hybrid waves and associated nonlinear effects

1994 ◽  
Vol T50 ◽  
pp. 75-80 ◽  
Author(s):  
P K Shukla ◽  
R Bingham ◽  
U de Angelis
Keyword(s):  
Large Amplitude ◽  
Nonlinear Effects ◽  
Lower Hybrid ◽  
Hybrid Waves ◽  
Lower Hybrid Waves

Nonlinear effects in two-layer large-amplitude geostrophic dynamics. Part 1. The strong-beta case

2000 ◽  
Vol 412 ◽  
pp. 125-160 ◽  
Author(s):  
RICHARD H. KARSTEN ◽  
GORDON E. SWATERS
Keyword(s):  
Large Amplitude ◽  
Nonlinear Effects ◽  
Breaking Waves ◽  
Short Wave ◽  
Finite Amplitude ◽  
Length Scale ◽  
Leading Order ◽  
Length Scales ◽  
Geostrophic Balance ◽  
Suitable Framework

Baroclinic large-amplitude geostrophic (LAG) models, which assume a leading-order geostrophic balance but allow for large-amplitude isopycnal deflections, provide a suitable framework to model the large-amplitude motions exhibited in frontal regions. The qualitative dynamical characterization of LAG models depends critically on the underlying length scale. If the length scale is sufficiently large, the effect of differential rotation, i.e. the β-effect, enters the dynamics at leading order. For smaller length scales, the β-effect, while non-negligible, does not enter the dynamics at leading order. These two dynamical limits are referred to as strong-β and weak-β models, respectively.A comprehensive description of the nonlinear dynamics associated with the strong- β models is given. In addition to establishing two new nonlinear stability theorems, we extend previous linear stability analyses to account for the finite-amplitude development of perturbed fronts. We determine whether the linear solutions are subject to nonlinear secondary instabilities and, in particular, a new long-wave–short-wave (LWSW) resonance, which is a possible source of rapid unstable growth at long length scales, is identified. The theoretical analyses are tested against numerical simulations. The simulations confirm the importance of the LWSW resonance in the development of the flow. Simulations show that instabilities associated with vanishing potential- vorticity gradients can develop into stable meanders, eddies or breaking waves. By examining models with different layer depths, we reveal how the dynamics associated with strong-β models qualitatively changes as the strength of the dynamic coupling between the barotropic and baroclinic motions varies.

Large amplitude ion-acoustic double layers in warm dusty plasma

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
S. L. Jain ◽  
R. S. Tiwari ◽  
M. K. Mishra
Keyword(s):  
Numerical Analysis ◽  
Mach Number ◽  
Large Amplitude ◽  
Double Layers ◽  
Nonlinear Structures ◽  
Dust Grains ◽  
Laboratory Plasma ◽  
Mobility Of Ions ◽  
Ion Acoustic ◽  
Charge Concentration

Large amplitude ion-acoustic double layer (IADL) is studied using Sagdeev's pseudo-potential technique in collisionless unmagnetized plasma comprising hot and cold Maxwellian population of electrons, warm adiabatic ions, and dust grains. Variation of both Mach number (M) and amplitude |φm| of large amplitude IADL with charge, concentration, and mass of heavily charged massive dust grains is investigated for both positive and negative dust in plasma. Our numerical analysis shows that system supports only rarefactive large amplitude IADL for the selected set of plasma parameters. Our investigations for both negative and positive dust grains reveal that ion temperature increases the mobility of ions, resulting in increase in the Mach number of IADL. The larger mobility of ions causes leakage of ions from localized region, resulting into decrease in the amplitude of IADL. Other parameters, e.g. temperature ratio of hot to cold electrons, charge, concentration, mass of heavily charged massive dust grains also play significant role in the properties and existence of double layers. Since it is well established that both positive and negative dust are found in space as well as laboratory plasma, and double layers have a tremendous role to play in astrophysics, we have included both positive and negative dust in our numerical analysis for the study of large amplitude IADL. Further data used for negative dust are close to experimentally observed data. Hence, it is anticipated that our parametric studies for heavily charged (both positive and negative) dust may be useful in understanding laboratory plasma experiments, identifying nonlinear structures in upper part of ionosphere and lower part of magnetosphere structures, and in theoretical research for the study of properties of nonlinear structures.

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