Local Measurements of Radial Plasma Velocity Fluctuations in the FT-2 Tokamak Using Equatorial Enhanced Scattering

2020 ◽  
Vol 46 (8) ◽  
pp. 767-770
Author(s):  
A. D. Gurchenko ◽  
E. Z. Gusakov ◽  
A. B. Altukhov ◽  
V. A. Ivanov ◽  
A. V. Sidorov ◽  
...  
Keyword(s):  
Plasma Velocity ◽  
Velocity Fluctuations ◽  
Local Measurements

scholarly journals Локальные измерения флуктуаций радиальной скорости плазмы в токамаке ФТ-2 с помощью экваториального усиленного рассеяния

2020 ◽  
Vol 46 (15) ◽  
pp. 39
Author(s):  
А.Д. Гурченко ◽  
Е.З. Гусаков ◽  
А.Б. Алтухов ◽  
В.А. Иванов ◽  
А.В. Сидоров ◽  
...  
Keyword(s):  
Small Angle ◽  
Density Fluctuations ◽  
Plasma Velocity ◽  
Velocity Fluctuations ◽  
The Core ◽  
Microwave Beam ◽  
Hybrid Resonance ◽  
Angle Scattering ◽  
Core Plasma ◽  
Local Measurements

The possibility of local measurements of the level of the radial plasma velocity fluctuations by the equatorial enhanced scattering of a narrow microwave beam in the upper hybrid resonance in the core plasma of a tokamak is demonstrated. The limitations of the proposed method are clarified at the periphery of the plasma, where the amplitude of density fluctuations grows and small-angle scattering of microwaves on them along the path to the upper hybrid resonance and back becomes significant.

Characteristics of Long-Period Flow Velocity Fluctuations around Tomakomai Harbor

1999 ◽  
Author(s):  
Hiroya Kinoshita ◽  
Hideki Hoshi ◽  
Youichi Atsumi ◽  
Shin-ichiro Sekiguchi ◽  
Toshihiko Yamashita
Keyword(s):  
Flow Velocity ◽  
Velocity Fluctuations ◽  
Long Period

scholarly journals Quantum Euler Relation for Local Measurements

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 889
Author(s):  
Akram Touil ◽  
Kevin Weber ◽  
Sebastian Deffner
Keyword(s):  
Quantum Systems ◽  
Quantum Measurements ◽  
Weak Coupling Regime ◽  
Local Quantum ◽  
Dissipation Model ◽  
Local Measurements ◽  
Euler Relation ◽  
Quantum Analog ◽  
Back Action ◽  
Classical Thermodynamics

In classical thermodynamics the Euler relation is an expression for the internal energy as a sum of the products of canonical pairs of extensive and intensive variables. For quantum systems the situation is more intricate, since one has to account for the effects of the measurement back action. To this end, we derive a quantum analog of the Euler relation, which is governed by the information retrieved by local quantum measurements. The validity of the relation is demonstrated for the collective dissipation model, where we find that thermodynamic behavior is exhibited in the weak-coupling regime.

scholarly journals An Islanding Detection Technique for Inverter-Based Distributed Generation in Microgrids

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 130
Author(s):  
Mazaher Karimi ◽  
Mohammad Farshad ◽  
Qiteng Hong ◽  
Hannu Laaksonen ◽  
Kimmo Kauhaniemi
Keyword(s):  
Distributed Generation ◽  
Phasor Measurement Units ◽  
Rate Of Change ◽  
Detection Technique ◽  
Islanding Detection ◽  
Simulation Studies ◽  
Local Measurements ◽  
Measurement Units ◽  
Utility Grid ◽  
Frequency Fluctuations

This article proposes a new passive islanding detection technique for inverter-based distributed generation (DG) in microgrids based on local synchrophasor measurements. The proposed method utilizes the voltage and current phasors measured at the DG connection point (point of connection, PoC). In this paper, the rate of change of voltages and the ratio of the voltage and current magnitudes (VoI index) at the PoC are monitored using micro-phasor measurement units. The developed local measurements based decentralized islanding detection technique is based on the VoI index in order to detect any kind of utility grid frequency fluctuations or oscillations and distinguishing them from islanding condition. The simulation studies confirm that the proposed scheme is accurate, robust, fast, and simple to implement for inverter-based DGs.

scholarly journals Three-dimensional analysis of intracycle velocity fluctuations in frontcrawl swimming

2010 ◽  
Vol 20 (1) ◽  
pp. 128-135 ◽  
Author(s):  
S. G. Psycharakis ◽  
R. Naemi ◽  
C. Connaboy ◽  
C. McCabe ◽  
R. H. Sanders
Keyword(s):  
Dimensional Analysis ◽  
Three Dimensional ◽  
Velocity Fluctuations

scholarly journals Fractal-induced 2D flexible net undulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Joon Seng Goh ◽  
Yeong Shiong Chiew ◽  
Ji Jinn Foo
Keyword(s):  
3D Reconstruction ◽  
Cross Section ◽  
Channel Cross Section ◽  
Time Varying ◽  
Blockage Ratio ◽  
Transient Time ◽  
Cross Sectional ◽  
Velocity Fluctuations ◽  
Square Grid ◽  
Multilength Scale

AbstractA net immersed in fractal-induced turbulence exhibit a transient time-varying deformation. The anisotropic, inhomogeneous square fractal grid (SFG) generated flow interacts with the flexible net to manifest as visible cross-sectional undulations. We hypothesize that the net’s response may provide a surrogate in expressing local turbulent strength. This is analysed as root-mean-squared velocity fluctuations in the net, displaying intensity patterns dependent on the grid conformation and grid-net separation. The net’s fluctuation strength is found to increase closer to the turbulator with higher thickness ratio while presenting stronger fluctuations compared to regular-square-grid (RSG) of equivalent blockage-ratio, σ. Our findings demonstrate a novel application where 3D-reconstruction of submerged nets is used to experimentally contrast the turbulence generated by RSG and multilength scale SFGs across the channel cross-section. The net’s response shows the unique turbulence developed from SFGs can induce 9 × higher average excitation to a net when compared against RSG of similar σ.

scholarly journals Decay of turbulence in a liquid metal duct flow with transverse magnetic field

2019 ◽  
Vol 867 ◽  
pp. 661-690 ◽  
Author(s):  
Oleg Zikanov ◽  
Dmitry Krasnov ◽  
Thomas Boeck ◽  
Semion Sukoriansky
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic Field ◽  
Large Scale ◽  
High Amplitude ◽  
Transverse Magnetic ◽  
Duct Flow ◽  
Velocity Fluctuations ◽  
Turbulence Decay ◽  
The Moment ◽  
Typical Length

Decay of honeycomb-generated turbulence in a duct with a static transverse magnetic field is studied via direct numerical simulations. The simulations follow the revealing experimental study of Sukoriansky et al. (Exp. Fluids, vol. 4 (1), 1986, pp. 11–16), in particular the paradoxical observation of high-amplitude velocity fluctuations, which exist in the downstream portion of the flow when the strong transverse magnetic field is imposed in the entire duct including the honeycomb exit, but not in other configurations. It is shown that the fluctuations are caused by the large-scale quasi-two-dimensional structures forming in the flow at the initial stages of the decay and surviving the magnetic suppression. Statistical turbulence properties, such as the energy decay curves, two-point correlations and typical length scales are computed. The study demonstrates that turbulence decay in the presence of a magnetic field is a complex phenomenon critically depending on the state of the flow at the moment the field is introduced.

High-output diesel engine heat transfer: Part 1 - comparison between piston heat flux and global energy balance

2021 ◽  
pp. 146808742110170
Author(s):  
Eric Gingrich ◽  
Michael Tess ◽  
Vamshi Korivi ◽  
Jaal Ghandhi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Diesel Engine ◽  
Surface Temperature ◽  
Fast Response ◽  
Temperature Data ◽  
Start Of Injection ◽  
Local Measurements ◽  
Surface Temperature Data ◽  
High Output

High-output diesel engine heat transfer measurements are presented in this paper, which is the first of a two-part series of papers. Local piston heat transfer, based on fast-response piston surface temperature data, is compared to global engine heat transfer based on thermodynamic data. A single-cylinder research engine was operated at multiple conditions, including very high-output cases – 30 bar IMEPg and 250 bar in-cylinder pressure. A wireless telemetry system was used to acquire fast-response piston surface temperature data, from which heat flux was calculated. An interpolation and averaging procedure was developed and a method to recover the steady-state portion of the heat flux based on the in-cylinder thermodynamic state was applied. The local measurements were spatially integrated to find total heat transfer, which was found to agree well with the global thermodynamic measurements. A delayed onset of the rise of spatially averaged heat flux was observed for later start of injection timings. The dataset is internally consistent, for example, the local measurements match the global values, which makes it well suited for heat transfer correlation development; this development is pursued in the second part of this paper.

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