scholarly journals Measurement of the velocity field in parametrically excited solitary waves

2014 ◽  
Vol 754 ◽  
pp. 590-604 ◽  
Author(s):  
Leonardo Gordillo ◽  
Nicolás Mujica

AbstractParametrically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of these waves using particle image velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is primarily composed of a subharmonic oscillatory component. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which we show to be as important as other crucial nonlinear terms in the current theory. Using vorticity equations, we show that the streaming pattern arises from the coupling of the potential bulk flow with the oscillating boundary layers on the vertical walls. Numerical simulations provide good agreement between this model and experiments.

A layer of water in a cylindrical tank is known to be capable of sustaining standing solitary waves within a certain parametric domain when the tank is excited under vertical oscillation. A new mode of forced waves is discovered to exist in a different parametric domain for rectangular tanks with the wave sloshing across the short side of the tank and with its profile modulated by one or more hyperbolic-tangent, or kink-wave-like envelopes. A theoretical explanation for the kink wave properties is provided. Experiments were performed to confirm their existence.


2003 ◽  
Vol 58 (5-6) ◽  
pp. 280-284
Author(s):  
J.-F. Zhang ◽  
Z.-M. Lu ◽  
Y.-L. Liu

By means of the Bäcklund transformation, a quite general variable separation solution of the (2+1)- dimensional long dispersive wave equation: λqt + qxx − 2q ∫ (qr)xdy = 0, λrt − rxx + 2r ∫ (qr)xdy= 0, is derived. In addition to some types of the usual localized structures such as dromion, lumps, ring soliton and oscillated dromion, breathers soliton, fractal-dromion, peakon, compacton, fractal and chaotic soliton structures can be constructed by selecting the arbitrary single valued functions appropriately, a new class of localized coherent structures, that is the folded solitary waves and foldons, in this system are found by selecting appropriate multi-valuded functions. These structures exhibit interesting novel features not found in one-dimensions. - PACS: 03.40.Kf., 02.30.Jr, 03.65.Ge.


2006 ◽  
Vol 61 (1-2) ◽  
pp. 53-59 ◽  
Author(s):  
Cheng-Lin Bai ◽  
Cheng-Jie Bai ◽  
Hong Zhao

Taking the new (2+1)-dimensional generalized Broer-Kaup system as an example, we obtain an exact variable separation excitation which can describe some quite universal (2+1)-dimensional physical models, with the help of the extended homogeneous balance method. Based on the derived excitation, a new class of combined structures, i. e., semifolded solitary waves and semifoldons, is defined and studied. The interactions of the semifolded localized structures are illustrated both analytically and graphically. - PACS numbers: 05.45.Yv, 02.30.Jr, 02.30.Ik


1995 ◽  
Vol 294 ◽  
pp. 123-154 ◽  
Author(s):  
H.-C. Chang ◽  
E. Demekhin ◽  
E. Kalaidin

Beyond a short transition region near the inlet, waves on a falling film evolve into distinct pulse-like solitary waves that dominate all subsequent interfacial dynamics. Numerical and physical experiments indicate that these localized structures can attract and repel each other. Attractive interaction through the capillary ripples of the pulses causes two pulses to coalesce into a bigger pulse which accelerates and precipitates further coalescence. This binary interaction between an ‘excited’ pulse after coalescence and its smaller front neighbour is the key mechanism that drives the observed wave dynamics. From symmetry arguments, two dominant modes for a solitary pulse are obtained and used to develop an inelastic coherent structure theory for binary interaction between an excited pulse and its front neighbour. The theory offers a simple dynamical system that quantitatively describes the binary interaction and promises to elucidate the complex wave dynamics on a falling film.


2008 ◽  
Vol 74 (4) ◽  
pp. 555-568
Author(s):  
MOULOUD TRIBECHE

AbstractSmall-amplitude electrostatic solitary waves are investigated in an unmagnetized dusty plasma with hot variable charge non-thermal dust grains. These nonlinear localized structures are small-amplitude self-consistent solutions of the Vlasov equation in which the dust response is non-Maxwellian. Localized solitary structures that may possibly occur are discussed and the dependence of their characteristics on physical parameters is traced. Our investigation may be taken as a prerequisite for the understanding of the electrostatic solitary waves that may occur in space dusty plasmas.


1994 ◽  
Vol 04 (05) ◽  
pp. 1135-1146 ◽  
Author(s):  
VLADIMIR I. NEKORKIN ◽  
MANUEL G. VELARDE

Propagating dissipative (localized) structures like solitary waves, pulses or “solitons,” “bound solitons,” and “chaotic” wave trains are shown to be solutions of a dissipation-modified Korteweg-de Vries equation that in particular appears in Marangoni-Bénard convection when a liquid layer is heated from the air side and in the description of internal waves in sheared, stably stratified fluid layers.


2018 ◽  
Vol 73 ◽  
pp. 70-79 ◽  
Author(s):  
W.Y. Duan ◽  
Z. Wang ◽  
B.B. Zhao ◽  
R.C. Ertekin ◽  
J.W. Kim

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