Resonant mode in the Earth’s thermosphere

2011 ◽  
Vol 17 (6) ◽  
pp. 74-76 ◽  
Author(s):  
O.K. Cheremnykh ◽  
Keyword(s):  
Resonant Mode

AN EXPERIMENT WHICH MEASURES RESONANT MODE CONVERSION IN He II

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-228-C6-229
Author(s):  
S. Garrett ◽  
S. Adams ◽  
S. Putterman ◽  
I. Rudnick
Keyword(s):  
Mode Conversion ◽  
Resonant Mode

Tire Vibrations

1977 ◽  
Vol 5 (4) ◽  
pp. 202-225 ◽  
Author(s):  
G. R. Potts ◽  
C. A. Bell ◽  
L. T. Charek ◽  
T. K. Roy
Keyword(s):  
Natural Frequencies ◽  
Standing Waves ◽  
Resonant Mode ◽  
Mode Shapes ◽  
Resonant Vibrations ◽  
Resonant Frequencies ◽  
Radial Tire ◽  
Analysis Techniques ◽  
Thin Ring ◽  
Good Agreement

Abstract Natural frequencies and vibrating motions are determined in terms of the material and geometric properties of a radial tire modeled as a thin ring on an elastic foundation. Experimental checks of resonant frequencies show good agreement. Forced vibration solutions obtained are shown to consist of a superposition of resonant vibrations, each rotating around the tire at a rate depending on the mode number and the tire rotational speed. Theoretical rolling speeds that are upper bounds at which standing waves occur are determined and checked experimentally. Digital Fourier transform, transfer function, and modal analysis techniques used to determine the resonant mode shapes of a radial tire reveal that antiresonances are the primary transmitters of vibration to the tire axle.

Printed Antennas Tuned by Transversely Magnetized Ferrite Operating at a Novel Resonant Mode

PIERS Online ◽  
2007 ◽  
Vol 3 (8) ◽  
pp. 1213-1216 ◽  
Author(s):  
Anestis Mavridis ◽  
George Kyriacou ◽  
J. N. Sahalos
Keyword(s):  
Resonant Mode ◽  
Printed Antennas

scholarly journals Acoustic Modeling and Vibration Characteristics of Supersonic Inlet Buzz

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2048
Author(s):  
Jianfeng Zhu ◽  
Wenguo Luo ◽  
Yuqing Wei ◽  
Cheng Yan ◽  
Yancheng You
Keyword(s):  
Numerical Simulations ◽  
Pressure Oscillation ◽  
Resonant Mode ◽  
Acoustic Model ◽  
Oscillation System ◽  
Nonlinear Simulation ◽  
Supersonic Inlet ◽  
Nonlinear Amplification ◽  
Oscillation Damping ◽  
The Ideal

The buzz phenomenon of a typical supersonic inlet is analyzed on the basis of numerical simulations and duct acoustic theory. Considering that the choked inlet could be treated as a duct with one end closed, a one-dimensional (1D) mathematical model based on the duct acoustic theory is proposed to describe the periodic pressure oscillation of the little buzz and the big buzz. The results of the acoustic model agree well with that of the numerical simulations and the experimental data. It could verify that the dominated oscillation patterns of the little buzz and the big buzz are closely related to the first and second resonant mode of the standing wave, respectively. The discrepancies between the numerical simulation and the ideal acoustic model might be attributed to the viscous damping in the fluid oscillation system. In order to explore the damping, a small perturbation jet is introduced to trigger the resonance of the buzz system and the nonlinear amplification effect of resonance might be helpful to estimate the damping. Through the comparison between the linear acoustic model and the nonlinear simulation, the calculated pressure oscillation damping of the little buzz and the big buzz are 0.33 and 0.16, which could be regarded as an estimation of real damping.

scholarly journals Graphene-based tunable hyperbolic microcavity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michał Dudek ◽  
Rafał Kowerdziej ◽  
Alessandro Pianelli ◽  
Janusz Parka
Keyword(s):  
Resonant Mode ◽  
Transverse Magnetic ◽  
Mid Infrared ◽  
Nanophotonic Devices ◽  
Wide Range ◽  
Fabry Perot ◽  
Hyperbolic Dispersion ◽  
Low Threshold ◽  
Infrared Frequencies ◽  
Infrared Wave

AbstractGraphene-based hyperbolic metamaterials provide a unique scaffold for designing nanophotonic devices with active functionalities. In this work, we have theoretically demonstrated that the characteristics of a polarization-dependent tunable hyperbolic microcavity in the mid-infrared frequencies could be realized by modulating the thickness of the dielectric layers, and thus breaking periodicity in a graphene-based hyperbolic metamaterial stack. Transmission of the tunable microcavity shows a Fabry–Perot resonant mode with a Q-factor > 20, and a sixfold local enhancement of electric field intensity. It was found that by varying the gating voltage of graphene from 2 to 8 V, the device could be self-regulated with respect to both the intensity (up to 30%) and spectrum (up to 2.1 µm). In addition, the switching of the device was considered over a wide range of incident angles for both the transverse electric and transverse magnetic modes. Finally, numerical analysis indicated that a topological transition between elliptic and type II hyperbolic dispersion could be actively switched. The proposed scheme represents a remarkably versatile platform for the mid-infrared wave manipulation and may find applications in many multi-functional architectures, including ultra-sensitive filters, low-threshold lasers, and photonic chips.

Magnetoelectric Alternator

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
R. V. Petrov ◽  
N. A. Kolesnikov ◽  
M. I. Bichurin
Keyword(s):  
Energy Harvesting ◽  
Magnetoelectric Effect ◽  
Electronic Devices ◽  
Synchronous Generator ◽  
Resonant Mode ◽  
Practical Application ◽  
Variable Voltage ◽  
Power Generation Equipment ◽  
High Power Consumption ◽  
Energy Harvesting Devices

AbstractThe article is devoted to researching the practical application of the magnetoelectric effect for the development of energy harvesting devices, in particular for the design of magnetoelectric synchronous generator. The energy harvesting devices are designed to provide by the energy of remote or nonvolatile electronic devices that don’t require the high power consumption. General dimensions of the generator were as follows: diameter of 12 cm, thickness of 2.4 cm. The model of generator comprising eight ME elements with dimensions of one element of 40×10×0.5 mm at the frequency of the alternating magnetic field of 38 Hz provides the output constant voltage of 1.12 V and current of 3.82 microamps. Variable voltage before the rectifier was of 1.7 V. Total generated power was of 4.28 µW. The studies of resonant and non-resonant mode of ME element were carried out. Resonance mode of ME element provides a much greater output power. Designed generator can be applied in the construction of wind power sets, hydrogenerators, turbogenerators and other power generation equipment.

RESONANCE OF NONMODAL PERTURBATIONS IN THE BATCHELOR VORTEX

2010 ◽  
Vol 24 (13) ◽  
pp. 1449-1452
Author(s):  
ZHI-WEI GUO ◽  
DE-JUN SUN
Keyword(s):  
Resonant Mode ◽  
Resonance Phenomenon ◽  
Mode Switch ◽  
Energy Growth ◽  
Optimal Energy ◽  
Maximum Value ◽  
Resonant Character ◽  
Swirl Parameter

The resonance phenomenon for nonmodal perturbation of Batchelor vortex is studied. For azimuthal wavenumber n = - 1, two resonant peaks appear and the left one is always dominant. For n = 1, the resonant character becomes very complicated. There is a resonant mode switch from right peak to left peak as swirl parameter q increases from 2 to infinity. The resonant wavenumber k is the largest when q approaches to infinity for n = - 1 while it is the smallest for n = 1. The maximum value of the optimal energy growth for n = 1 is at q approaches to infinity, whereas it decreases monotonically as q increases for n = - 1. The resonance for n = - 1 is the more important one.

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