scholarly journals Combination Mode of Internal Waves Generated by Surface Wave Propagating over Two Muddy Sea Beds

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ray-Yeng Yang ◽  
Hwung Hweng Hwung
Keyword(s):  
Surface Wave ◽  
Surface Water ◽  
Internal Waves ◽  
Water Wave ◽  
Nonlinear Response ◽  
Progressive Wave ◽  
Layer System ◽  
Long Wavelength ◽  
Sea Bed ◽  
Combination Mode

When surface wave propagating over the two layer system usually induces internal wave in three different modes: they are external, internal and combination. In the present study, the nonlinear response of an initially flat sea bed, with two muddy sections, to a monochromatic surface progressive wave was investigated. From this theoretical result, it shows that a surface water wave progressing over two different muddy sections, the surface wave will excite two opposite-traveling short interfacial waves, forming a nearly standing wave at the interface of the fresh water and the muddy layer. Meanwhile, two opposite-outgoing “mud” waves each with very long wavelength will be simultaneously induced at the interface of two muddy sections. As a result, the amplitudes of the two short internal waves are found to grow exponentially in time. Furthermore, it will be much difficult to excite the internal waves when surface water wave progressing over two muddy sections with the large density gap.

Resonant Generation of Internal Waves on Two Muddy Sea Beds by a Progressive Surface Wave

2009 ◽  
Author(s):  
Ray-Yeng Yang ◽  
Hwung-Hweng Hwung ◽  
Igor V. Shugan
Keyword(s):  
Surface Wave ◽  
Surface Water ◽  
Internal Waves ◽  
Water Wave ◽  
Evolution Equations ◽  
Wave Attenuation ◽  
Multiple Scale ◽  
Layer System ◽  
Practical Applications ◽  
Sea Bed

The present work is motivated by recent studies on the interaction between a progressive surface wave and the nearly standing subharmonic internal waves in a two-layer system. It is well known that the loading of progressive surface waves, a silty sediment bed was repeatedly and extensively fluidized. The great interest in understanding this phenomenon was induced by the practical applications in sediment transport, wave attenuation, and the design of marine structures. The nonlinear response of an initially flat sea bed, with two muddy sections, to a monochromatic surface progressive wave was investigated in the present study. Based on an analysis similar to that of Hill & Foda’s (1998), the multiple scale perturbation method was adopted and the boundary value problem was expanded in a power series of the surface-wave steepness. The linear harmonics and the conditions for resonance were obtained by the leading order. While, the temporal evolution equations for the internal-wave amplitudes were investigated by a second-order analysis. It was found that result for equal density of two muddy sections is similar to that of Hill & Foda’s (1998). Two opposite-traveling internal “mud” waves are selectively excited and formed a resonant triad with the progressive surface wave. However for a surface water wave progressing over two different muddy sections, the surface wave will also excite only two opposite-traveling short interfacial waves, forming a nearly standing wave at the interface of the fresh water and the muddy layer. Meanwhile, two opposite-outgoing “mud” waves each with very long wavelength will be simultaneously induced at the interface of two muddy sections. As a result, the amplitudes of the two short internal waves are found to grow exponentially in time. Furthermore, it will be much difficult to excite the internal waves when surface water wave progressing over two muddy sections with the large density gap.

scholarly journals Nonlinear tsunami generation mechanism

2001 ◽  
Vol 1 (4) ◽  
pp. 251-253 ◽  
Author(s):  
M. A. Nosov ◽  
S. N. Skachko
Keyword(s):  
Surface Wave ◽  
Surface Water ◽  
High Frequency ◽  
Water Wave ◽  
Wave Amplitude ◽  
Water Layer ◽  
Generation Mechanism ◽  
Tsunami Generation ◽  
Constant Depth ◽  
Nonlinear Mechanism

Abstract. The nonlinear mechanism of long gravitational surface water wave generation by high-frequency bottom oscillations in a water layer of constant depth is investigated analytically. The connection between the surface wave amplitude and the parameters of bottom oscillations and source length is investigated.

Subharmonic resonance of short internal standing waves by progressive surface waves

1996 ◽  
Vol 321 ◽  
pp. 217-233 ◽  
Author(s):  
D. F. Hill ◽  
M. A. Foda
Keyword(s):  
Surface Wave ◽  
Internal Wave ◽  
Surface Waves ◽  
Internal Waves ◽  
Growth Rates ◽  
Evolution Equations ◽  
Standing Waves ◽  
Second Order ◽  
Inviscid Limit ◽  
Initial Growth

Experimental evidence and a theoretical formulation describing the interaction between a progressive surface wave and a nearly standing subharmonic internal wave in a two-layer system are presented. Laboratory investigations into the dynamics of an interface between water and a fluidized sediment bed reveal that progressive surface waves can excite short standing waves at this interface. The corresponding theoretical analysis is second order and specifically considers the case where the internal wave, composed of two oppositely travelling harmonics, is much shorter than the surface wave. Furthermore, the analysis is limited to the case where the internal waves are small, so that only the initial growth is described. Approximate solution to the nonlinear boundary value problem is facilitated through a perturbation expansion in surface wave steepness. When certain resonance conditions are imposed, quadratic interactions between any two of the harmonics are in phase with the third, yielding a resonant triad. At the second order, evolution equations are derived for the internal wave amplitudes. Solution of these equations in the inviscid limit reveals that, at this order, the growth rates for the internal waves are purely imaginary. The introduction of viscosity into the analysis has the effect of modifying the evolution equations so that the growth rates are complex. As a result, the amplitudes of the internal waves are found to grow exponentially in time. Physically, the viscosity has the effect of adjusting the phase of the pressure so that there is net work done on the internal waves. The growth rates are, in addition, shown to be functions of the density ratio of the two fluids, the fluid layer depths, and the surface wave conditions.

scholarly journals Control of the nonlinear response of bulk GaAs induced by long-wavelength infrared pulses

2019 ◽  
Vol 27 (21) ◽  
pp. 30462 ◽  
Author(s):  
D. Matteo ◽  
J. Pigeon ◽  
S. Ya. Tochitsky ◽  
U. Huttner ◽  
M. Kira ◽  
...  
Keyword(s):  
Nonlinear Response ◽  
Bulk Gaas ◽  
Long Wavelength ◽  
Long Wavelength Infrared

scholarly journals Brief communication: Modulation instability of internal waves in a smoothly stratified shallow fluid with a constant buoyancy frequency

2019 ◽  
Vol 19 (3) ◽  
pp. 583-587 ◽  
Author(s):  
Kwok Wing Chow ◽  
Hiu Ning Chan ◽  
Roger H. J. Grimshaw
Keyword(s):  
Numerical Simulation ◽  
Surface Wave ◽  
Internal Waves ◽  
Modulation Instability ◽  
Rogue Waves ◽  
Buoyancy Frequency ◽  
Spontaneous Generation ◽  
Large Displacements ◽  
Analytical Treatment ◽  
Intermediate Depth

Abstract. Unexpectedly large displacements in the interior of the oceans are studied through the dynamics of packets of internal waves, where the evolution of these displacements is governed by the nonlinear Schrödinger equation. In cases with a constant buoyancy frequency, analytical treatment can be performed. While modulation instability in surface wave packets only arises for sufficiently deep water, “rogue” internal waves may occur in shallow water and intermediate depth regimes. A dependence on the stratification parameter and the choice of internal modes can be demonstrated explicitly. The spontaneous generation of rogue waves is tested here via numerical simulation.

Non-Thermal and Dust Charge Effects on Surface Ion Waves in Semi-Bound Lorentzian Plasmas

2006 ◽  
Vol 61 (7-8) ◽  
pp. 323-329 ◽  
Author(s):  
Jae-Hoon Song ◽  
Young-Dae Jung
Keyword(s):  
Surface Wave ◽  
Phase Velocity ◽  
Spectral Index ◽  
Charged Dust ◽  
Dust Grains ◽  
Charge Effects ◽  
Long Wavelength ◽  
Dust Charge ◽  
Ion Waves ◽  
Positively Charged

The non-thermal and dust charge effects on a surface electrostatic ion plasma wave are investigated in a semi-bound magnetized dusty Lorentzian plasma. The results show that the phase velocity of the surface wave with negatively charged dust grains is greater than that with positively charged dust grains or that with neutral dust grains. It is also found that the phase velocity increases with increasing the spectral index of the plasma. For the long wavelength domain, however, the phase velocity of the surface wave is found to be almost independent of the spectral index.

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