Three-dimensional tidal sand waves

The process which leads to the formation of three-dimensional sand waves is investigated by means of a stability analysis which considers the time development of a small-amplitude bottom perturbation of a shallow tidal sea. The weakly nonlinear interaction of a triad of resonant harmonic components of the bottom perturbation is considered. The results show that the investigated resonance mechanism can trigger the formation of a three-dimensional bottom pattern similar to that observed in the field.

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Three Waves Interaction of Disterbanced in the Hypersonic Boundary Layer

Siberian Journal of Physics ◽

10.54362/1818-7919-2008-3-3-39-45 ◽

2008 ◽

Vol 3 (3) ◽

pp. 39-45

Author(s):

Sergey A. Gaponov ◽

Natalya M. Terekhova ◽

Boris V. Smorodsky

Keyword(s):

Boundary Layer ◽

Nonlinear Interaction ◽

Three Dimensional ◽

Hypersonic Boundary Layer ◽

Nonlinear Interactions ◽

Threshold Values ◽

Weakly Nonlinear ◽

Intensity Threshold ◽

Tollmien Schlichting ◽

Waves Interaction

In frames of the weakly nonlinear stability theory a disturbances interaction in a hypersonic boundary layer is considered. It is established that nonlinear interaction in a hypersonic boundary layer is probably, it is carried out between waves of the different nature (acoustical and vortical) in a parametric resonance regime. For three-dimensional vortical waves similar interaction is more intensively. The plane acoustical wave which increases more intensively in comparison with the threedimensional is the pumping wave. There are intensity threshold values of the nonlinear interaction beginning and threshold values of the explosive growth beginning. It is possible to expect, that nonlinear interactions for vortical waves which are carried out in wide frequency band can lead to a package growth of Tollmien-Schlichting waves.

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The formation of tidal sand waves: Fully three-dimensional versus shallow water approaches

Continental Shelf Research ◽

10.1016/j.csr.2011.03.005 ◽

2011 ◽

Vol 31 (9) ◽

pp. 990-996 ◽

Cited By ~ 7

Author(s):

Paolo Blondeaux ◽

Giovanna Vittori

Keyword(s):

Shallow Water ◽

Three Dimensional ◽

Sand Waves ◽

Tidal Sand

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Stability of weakly nonlinear ion sound waves with finite ion temperature

Journal of Plasma Physics ◽

10.1017/s0022377800022959 ◽

1981 ◽

Vol 25 (1) ◽

pp. 81-87 ◽

Cited By ~ 4

Author(s):

E. Infeld ◽

G. Rowlands

Keyword(s):

Acoustic Waves ◽

Thermal Effects ◽

Small Amplitude ◽

Modulation Instability ◽

Three Dimensional ◽

Three Dimensions ◽

Sound Waves ◽

Ion Temperature ◽

Ion Acoustic Waves ◽

Weakly Nonlinear

The modulation instability of small-amplitude ion-acoustic waves is investigated in three dimensions for Ti<0 (ion temperature non-zero). Relevance of results to an experiment of Watanabe is discussed. Instabilities present in this experiment are seen to be due to three-dimensional rather than thermal effects and would also appear for Ti = 0.

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