scholarly journals The Inhomogeneous Waves in a Rotating Piezoelectric Body

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoguang Yuan ◽  
Si Chen
Keyword(s):  
Critical Point ◽  
Rotation Speed ◽  
Frame Of Reference ◽  
Rotating Frame ◽  
Piezoelectric Body ◽  
Propagation Angle ◽  
Wave Velocities ◽  
Wave Characteristics ◽  
Inhomogeneous Waves ◽  
The Waves

This paper presents the analysis and numerical results of rotation, propagation angle, and attenuation angle upon the waves propagating in the piezoelectric body. Via considering the centripetal and Coriolis accelerations in the piezoelectric equations with respect to a rotating frame of reference, wave velocities and attenuations are derived and plotted graphically. It is demonstrated that rotation speed vector can affect wave velocities and make the piezoelectric body behaves as if it was damping. Besides, the effects of propagation angle and attenuation angle are presented. Critical point is found when rotation speed is equal to wave frequency, around which wave characteristics change drastically.

scholarly journals Observation of mesospheric gravity waves at Comandante Ferraz Antarctica Station (62° S)

2009 ◽  
Vol 27 (6) ◽  
pp. 2593-2598 ◽  
Author(s):  
J. V. Bageston ◽  
C. M. Wrasse ◽  
D. Gobbi ◽  
H. Takahashi ◽  
P. B. Souza
Keyword(s):  
Gravity Waves ◽  
Weather Conditions ◽  
Propagation Direction ◽  
Cyclonic Activity ◽  
Wave Source ◽  
Cold Fronts ◽  
Wave Velocities ◽  
Orographic Forcing ◽  
Sky Imager ◽  
The Waves

Abstract. An airglow all-sky imager was operated at Comandante Ferraz Antarctica Station (62.1° S, 58.4° W), between April and October of 2007. Mesospheric gravity waves were observed using the OH airglow layer during 43 nights with good weather conditions. The waves presented horizontal wavelengths between 10 and 60 km and observed periods mainly distributed between 5 and 20 min. The observed phase speeds range between 5 m/s and 115 m/s; the majority of the wave velocities were between 10 and 60 m/s. The waves showed a preferential propagation direction towards the southwest in winter (May to July), while during spring (August to October) there was an anisotropy with a preferential propagation direction towards the northwest. Unusual mesospheric fronts were also observed. The most probable wave source could be associated to orographic forcing, cold fronts or strong cyclonic activity in the Antarctica Peninsula.

scholarly journals Turbulent structures in cylindrical density currents in a rotating frame of reference

2018 ◽  
Vol 19 (6) ◽  
pp. 463-492 ◽  
Author(s):  
Jorge S. Salinas ◽  
Mariano I. Cantero ◽  
Enzo A. Dari ◽  
Thomas Bonometti
Keyword(s):  
Frame Of Reference ◽  
Rotating Frame ◽  
Density Currents ◽  
Turbulent Structures

scholarly journals Stability of Periodic Planetary-Type Orbits of the General Planar N-Body Problem

1979 ◽  
Vol 81 ◽  
pp. 23-28
Author(s):  
John D. Hadjidemetriou
Keyword(s):  
Periodic Orbits ◽  
Body Problem ◽  
Frame Of Reference ◽  
Rotating Frame ◽  
N Body Problem ◽  
Families Of Periodic Orbits ◽  
Special Case

It is known that families of periodic orbits in the general N-body problem (N≥3) exist, in a rotating frame of reference (Hadjidemetriou 1975, 1977). A special case of the above families of periodic orbits are the periodic orbits of the planetary type. In this latter case only one body, which we shall call sun, is the more massive one and the rest N-1 bodies, which we shall call planets, have small but not negligible masses. The aim of this paper is to study the properties of the families of periodic planetary-type orbits, with particular attention to stability. To make the presentation clearer, we shall start first with the case N=3 and we shall extend the results to N>3. We shall discuss planar orbits only.

Solutions of barotropic trapped waves around seamounts

2010 ◽  
Vol 661 ◽  
pp. 32-44 ◽  
Author(s):  
LUIS ZAVALA SANSÓN
Keyword(s):  
Positive Real Number ◽  
Radial Distance ◽  
Phase Speed ◽  
Trapped Waves ◽  
Positive Real ◽  
Wave Characteristics ◽  
Sharp Cone ◽  
The Waves ◽  
Wide Family ◽  
Special Case

In this paper, solutions of free, barotropic waves around axisymmetric seamounts are derived. Even though this type of oscillation has been studied before, we revisit this problem for two main reasons: (i) the linear, barotropic, shallow-water equations with a rigid lid are now solved with no further approximations, in contrast with previous studies; (ii) the solutions are applied to a wide family of seamounts with profiles proportional to exp(rs), with r being the radial distance from the centre of the mountain and s any positive real number. (Most previous works are restricted to the special case s = 2.) The resulting dispersion relation possesses a remarkable simplicity that reveals a number of wave characteristics, for instance, the discrete wave frequencies and the angular phase speed of the waves around the seamount are easily derived as a function of the seamount shape. By varying the shape parameter one can study trapped waves around flat-topped seamounts or guyots (s > 2) or sharp, cone-shaped topographies (s < 2).

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