scholarly journals Transient analysis of power loss density with time-harmonic electromagnetic waves in Debye media

2021 ◽  
Vol 8 (11) ◽  
Author(s):  
Jiaqi Zhong ◽  
Shan Liang ◽  
Yong Chen ◽  
Jiajia Tan
Keyword(s):  
Power Loss ◽  
Electromagnetic Waves ◽  
Transient Analysis ◽  
Time Domain Analysis ◽  
Conservation Equation ◽  
Analysis Method ◽  
Energy Conservation Equation ◽  
Time Harmonic ◽  
The Time Domain ◽  
Poynting Theorem

Due to the complex permittivity, it is difficult to directly clarify the transient mechanism between electromagnetic waves and Debye media. To overcome the above problem, the temporal relationship between the electromagnetic waves and permittivity is explicitly derived by applying the Fourier inversion and introducing the remnant displacement. With the help of the Poynting theorem and energy conservation equation, the transient power loss density is derived to describe the transient dissipation of electromagnetic field and the mechanism on phase displacement has been explicitly revealed. Besides, the unique solution can be obtained by applying the time-domain analysis method rather than involving the frequency-domain characteristics. The effectiveness of transient analysis is demonstrated by giving a comparison simulation on one-dimensional example.

Signal Acquisition and Analysis of Shaft Unbalance Vibration Test

2014 ◽  
Vol 945-949 ◽  
pp. 1090-1093
Author(s):  
Hai Peng Zhang ◽  
Hong Wu Chen ◽  
Bin Hu ◽  
Cheng Tian
Keyword(s):  
Fault Diagnosis ◽  
Time Domain ◽  
Time Domain Analysis ◽  
Rotating Machinery ◽  
Vibration Test ◽  
Signal Acquisition ◽  
Analysis Method ◽  
Characteristic Parameters ◽  
Test Platform ◽  
The Time Domain

This paper simulated the unbalance vibration conditions by the vibration test platform, measuring some common characteristic parameters of unbalance vibration fault diagnosis. This paper chose the time-domain analysis method, processing the characteristic parameters of the test, so as to achieve the purpose of vibration diagnosis. Through a large number of experimental data, this paper verified the feasibility and the effectiveness of the proposed approach to the unbalance fault diagnosis. The method proposed in this paper not only can be applied to unbalance fault diagnosis, but also can be promoted to apply to the fault diagnosis of other rotating machinery.

scholarly journals Analysis Method for the Heating of the Human Eye Exposed to High Frequency Electromagnetic Fields

2007 ◽  
Vol 3 (1) ◽  
pp. 3 ◽  
Author(s):  
Andrés Peratta ◽  
Dragan Poljak
Keyword(s):  
Electromagnetic Scattering ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Specific Absorption Rate ◽  
Scattering Problem ◽  
Analysis Method ◽  
Human Eye ◽  
Time Harmonic ◽  
Standard Finite Element Method ◽  
Frequency Radiation

The paper studies the thermal rise in the human eye caused by time harmonic electromagnetic waves. An eye has been illuminated by a high frequency plane wave with powerdensity 5.0 mW/cm2. Such a problem has been considered as an electromagnetic scattering problem since part of EM energy is transmitted to the eye and part of it is reflected. The total electric field inside an eye and related Specific Absorption Rate (SAR) has been calculated in a frequency range from 0.7 to 4.4 GHz via a hybrid BEM/FEM approach. Knowing the SAR distribution inside the eye provides the calculation of related temperature rise in the human eye due to high frequency radiation by solving Bio-Heat Transfer Equation via standard finite element method.

Mechanics and Pretreatment Research of Vibration Signals for the Numerical Control Machine

2013 ◽  
Vol 676 ◽  
pp. 162-165
Author(s):  
Er Bao Peng ◽  
Hong Ge Zhang ◽  
Hong Ying Wang
Keyword(s):  
Function Analysis ◽  
Time Domain Analysis ◽  
Analysis Data ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Numerical Control ◽  
Analysis Method ◽  
Vibration Signals ◽  
The Time Domain ◽  
Control Machine

To study vibration signals processing mechanics and the analysis method of the numerical control machine. vibration signals analysis method include time and frequent domain analysis: the time domain analysis mainly has the statistical analysis and the correlation function analysis. frequency domain analysis include spectral analysis, cepstrum analysis, data envelopment analysis. vibration signals pretreatment is the most commonly used and effective method on the mechanical device condition monitor and the failure diagnosis.

scholarly journals Application of Multi-Branch Cauer Circuits in the Analysis of Electromagnetic Transducers Used in Wireless Transfer Power Systems

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2052
Author(s):  
Milena Kurzawa ◽  
Cezary Jędryczka ◽  
Rafał M. Wojciechowski
Keyword(s):  
Power Systems ◽  
Field Model ◽  
Wireless Power Transfer ◽  
Equivalent Model ◽  
Power Transfer ◽  
Wireless Power ◽  
The Finite Element Method ◽  
Harmonic Field ◽  
Time Harmonic ◽  
The Time Domain

In this paper, the feasibility of applying a multi-branch equivalent model employing first- and second-order Cauer circuits for the analysis of electromagnetic transducers used in systems of wireless power transfer is discussed. A method of formulating an equivalent model (EqM) is presented, and an example is shown for a wireless power transfer system (WPTS) consisting of an air transformer with field concentrators. A method is proposed to synthesize the EqM of the considered transducer based on the time-harmonic field model, an optimization algorithm employing the evolution strategy (ES) and the equivalent Cauer circuits. A comparative analysis of the performance of the considered WPTS under high-frequency voltage supply calculated using the proposed EqM and a 3D field model in the time domain using the finite element method (FEM) was carried out. The selected results of the conducted analysis are presented and discussed.

scholarly journals Multiple conductances in the large K+ channel from Chara corallina shown by a transient analysis method

1992 ◽  
Vol 61 (3) ◽  
pp. 736-749 ◽  
Author(s):  
S.D. Tyerman ◽  
B.R. Terry ◽  
G.P. Findlay
Keyword(s):  
Transient Analysis ◽  
Chara Corallina ◽  
K Channel ◽  
Analysis Method

Experimental Study on the Performance of Constrained Damped Rail Vibration Reduction

2011 ◽  
Vol 42 (10) ◽  
pp. 9-14
Author(s):  
L.Y. Liu ◽  
J.Y. Li ◽  
X.J. Yin
Keyword(s):  
Experimental Study ◽  
Time Domain ◽  
Vibration Amplitude ◽  
Impact Load ◽  
Vibration Reduction ◽  
Time Domain Analysis ◽  
Experimental Basis ◽  
Vibration Acceleration ◽  
The Time Domain ◽  
Vibration Performance

To study the vibration reduction performance of damped rail, we take the standard rail and labyrinth constrained damped rail as the study target. By testing the vibration performance of both standard rail and labyrinth constrained damped rail in an anechoic room, we use the time-domain analysis to study the vibration changes with time passing. The results showed that: the labyrinth constrained damped rail vibration can effectively reduce the vibration amplitude and duration. Under the radial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 5% −19%, time of vibration and attenuation greater than 94%; under the axial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 9% −21%, time of vibration and attenuation greater than 92%. The results have provided an experimental basis for the design of new constrained damped rail.

Heat Transfer Analysis of a Novel Pressurized Air Receiver for Concentrated Solar Power via Combined Cycles

2009 ◽  
Vol 1 (4) ◽  
Author(s):  
I. Hischier ◽  
D. Hess ◽  
W. Lipiński ◽  
M. Modest ◽  
A. Steinfeld
Keyword(s):  
Heat Transfer ◽  
Thermal Efficiency ◽  
Porous Ceramic ◽  
Conservation Equation ◽  
Heat Transfer Analysis ◽  
Operational Parameters ◽  
Small Aperture ◽  
Solar Absorber ◽  
Energy Conservation Equation ◽  
Combined Cycles

A novel design of a high-temperature pressurized solar air receiver for power generation via combined Brayton–Rankine cycles is proposed. It consists of an annular reticulate porous ceramic (RPC) bounded by two concentric cylinders. The inner cylinder, which serves as the solar absorber, has a cavity-type configuration and a small aperture for the access of concentrated solar radiation. Absorbed heat is transferred by conduction, radiation, and convection to the pressurized air flowing across the RPC. A 2D steady-state energy conservation equation coupling the three modes of heat transfer is formulated and solved by the finite volume technique and by applying the Rosseland diffusion, P1, and Monte Carlo radiation methods. Key results include the temperature distribution and thermal efficiency as a function of the geometrical and operational parameters. For a solar concentration ratio of 3000 suns, the outlet air temperature reaches 1000°C at 10 bars, yielding a thermal efficiency of 78%.

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