Period Multiplication in a Continuous Time Series of Radio-Frequency DBDs at Atmospheric Pressure

2012 ◽  
Vol 11 (4) ◽  
pp. 1226-1235 ◽  
Author(s):  
Jiao Zhang ◽  
Yanhui Wang ◽  
Dezhen Wang
Keyword(s):  
Time Series ◽  
Radio Frequency ◽  
Atmospheric Pressure ◽  
Model Simulation ◽  
Fluid Model ◽  
Dissipative System ◽  
Period Doubling ◽  
Periodic Oscillation ◽  
Strong Nonlinearity ◽  
Nonlinear Behaviors

AbstractAs a spatially extended dissipative system with strong nonlinearity the radio-frequency (rf) dielectric-barrier discharges (DBDs) at atmospheric pressure possess complex spatiotemporal nonlinear behaviors. In this paper, the time-domain nonlinear behaviors of rf DBD in atmospheric argon are studied numerically by a one-dimensional fluid model. Simulation results show that, under appropriate controlling parameters, the rf DBD can undergo a transition from single-period state to chaos through period doubling bifurcation with increasing discharge time, i.e., the regular periodic oscillation and chaos can coexist in a long time series of the atmospheric-pressure rf DBD. With increasing applied voltage amplitude, the duration of the periodic oscillation reduces gradually and chaotic zone increases, and finally the whole discharge series becomes completely chaotic state. This is different from conventional period doubling route to chaos. Moreover, the spatial characteristics of rf period-doubling discharge and chaos, as well as the parameter range of various discharge behaviors occurring are also investigated in this paper.

scholarly journals Global model simulation of OH production in pulsed-DC atmospheric pressure helium-air plasma jets

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 375-382
Author(s):  
Saša Gocić ◽  
Željko Mladenović
Keyword(s):  
Atmospheric Pressure ◽  
Model Simulation ◽  
Fluid Model ◽  
Plasma Jets ◽  
Global Model ◽  
Oh Radicals ◽  
Air Plasma ◽  
Pulsed Dc ◽  
Main Production

AbstractThe results of global model simulation of an atmospheric pressure pulsed-DC helium plasma jet propagated in humid air, compared to the results of fluid model, are presented in this paper. The primary tasks of presented simulation were determination of the density and the main production pathways of OH radicals. The calculation reveals that global model gives higher OH densities than fluid model, especially at higher electron temperatures. This overestimation is mainly caused by the intrinsic assumptions of the global model, which impose limitations on its application for modelling of very transient physical processes such are streamers or plasma bullets. The main OH production and loss processes are well recognized by global model, and additional mechanisms are involved with respect to the case of fluid modelling. According to the presented results, global model will give satisfactory assessment of OH density and overall chemical composition of modelled plasmas, if the air fraction, electron density and temperature are correctly determined.

scholarly journals Period-doubling bifurcation analysis and chaos control for load torque using FLC

2021 ◽  
Author(s):  
Eman Moustafa ◽  
Abdel-Azem Sobaih ◽  
Belal Abozalam ◽  
Amged Sayed A. Mahmoud
Keyword(s):  
Floquet Theory ◽  
Chaos Control ◽  
Fuzzy Logic Controller ◽  
Chaotic Behavior ◽  
Period Doubling ◽  
Parameter Variation ◽  
Period Doubling Bifurcation ◽  
Load Torque ◽  
Nonlinear Behaviors ◽  
Scientific Fields

AbstractChaotic phenomena are observed in several practical and scientific fields; however, the chaos is harmful to systems as they can lead them to be unstable. Consequently, the purpose of this study is to analyze the bifurcation of permanent magnet direct current (PMDC) motor and develop a controller that can suppress chaotic behavior resulted from parameter variation such as the loading effect. The nonlinear behaviors of PMDC motors were investigated by time-domain waveform, phase portrait, and Floquet theory. By varying the load torque, a period-doubling bifurcation appeared which in turn led to chaotic behavior in the system. So, a fuzzy logic controller and developing the Floquet theory techniques are applied to eliminate the bifurcation and the chaos effects. The controller is used to enhance the performance of the system by getting a faster response without overshoot or oscillation, moreover, tends to reduce the steady-state error while maintaining its stability. The simulation results emphasize that fuzzy control provides better performance than that obtained from the other controller.

scholarly journals Onboard Radio Frequency Interference as the Origin of Inter-Satellite Biases for Microwave Humidity Sounders

2019 ◽  
Vol 11 (7) ◽  
pp. 866 ◽  
Author(s):  
Imke Hans ◽  
Martin Burgdorf ◽  
Stefan A. Buehler
Keyword(s):  
Time Series ◽  
Radio Frequency ◽  
Time Dependent ◽  
Radio Frequency Interference ◽  
Climate Variables ◽  
Compelling Evidence ◽  
Climate Data ◽  
The Earth ◽  
Correction Scheme

Understanding the causes of inter-satellite biases in climate data records from observations of the Earth is crucial for constructing a consistent time series of the essential climate variables. In this article, we analyse the strong scan- and time-dependent biases observed for the microwave humidity sounders on board the NOAA-16 and NOAA-19 satellites. We find compelling evidence that radio frequency interference (RFI) is the cause of the biases. We also devise a correction scheme for the raw count signals for the instruments to mitigate the effect of RFI. Our results show that the RFI-corrected, recalibrated data exhibit distinctly reduced biases and provide consistent time series.

The driving frequency effects on the atmospheric pressure corona jet plasmas from low frequency to radio frequency

2011 ◽  
Vol 18 (4) ◽  
pp. 043503 ◽  
Author(s):  
Dan Bee Kim ◽  
H. Jung ◽  
B. Gweon ◽  
S. Y. Moon ◽  
J. K. Rhee ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Driving Frequency ◽  
Frequency Effects

A self-consistent fluid model for radio-frequency discharges in SiH4–H2 compared to experiments

1997 ◽  
Vol 82 (5) ◽  
pp. 2060-2071 ◽  
Author(s):  
G. J. Nienhuis ◽  
W. J. Goedheer ◽  
E. A. G. Hamers ◽  
W. G. J. H. M. van Sark ◽  
J. Bezemer
Keyword(s):  
Radio Frequency ◽  
Fluid Model ◽  
Self Consistent ◽  
Radio Frequency Discharges

scholarly journals Analysis of long-term observations of the groundwater level In an aseismic region

2019 ◽  
pp. 47-67
Author(s):  
A. A. Lyubushin ◽  
O. S. Kazantseva ◽  
A. B. Manukin
Keyword(s):  
Time Series ◽  
Groundwater Level ◽  
Atmospheric Pressure ◽  
Active Regions ◽  
Sampling Interval ◽  
Pressure Effects ◽  
Adaptive Compensation ◽  
Groundwater Level Fluctuations ◽  
And Cluster Analysis

The results of the analysis of continuous precise time series of atmospheric pressure and groundwater level fluctuations in a well drilled to a depth of 400 m in the territory of Moscow are presented. The observations are remarkable in terms of their duration of more than 22 years (from February 2, 1993 to April 4, 2015) and by the sampling interval of 10 min. These long observations are suitable for exploring the stationarity of the properties of hydrogeological time series in a seismically quiet region, which is important from the methodological standpoint for interpreting the similar observations in seismically active regions aimed at earthquake prediction. Factor and cluster analysis applied to the sequence of multivariate vectors ofthe statistical properties of groundwater level time series in the successive 10-day windows after adaptive compensation for atmospheric pressure effects distinguish five different statistically significant states of the time series with the transitions between them. An attempt to geophysically interpret the revealed states is made. Two significant periods – 46 and 275 days – are established by spectral analysis of the sequence of the transitions times between the clusters.

Sign in / Sign up

Export Citation Format

Share Document