scholarly journals Local Magnetohydrodynamic Characteristics of the Plasma Stream generated by MPC

10.14311/1733 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Tatyana N. Cherednychenko ◽  
Igor E. Garkusha ◽  
Vladimir V. Chebotarev ◽  
Dmytro G. Solyakov ◽  
Yuriy V. Petrov ◽  
...  
Keyword(s):  
Electric Current ◽  
Discharge Current ◽  
Radiation Power ◽  
Operation Mode ◽  
Electrical Current ◽  
Plasma Stream ◽  
Total Discharge Current ◽  
Injection Power ◽  
Wave Range ◽  
Total Discharge

This paper investigates the spatial distributions of electrical current which flows inside the plasma stream generated by a magnetoplasma compressor (MPC). Two different modes of MPC operation with different gas supply scenarios have been applied in the experiments presented here. The first is the operation mode with a pulse injection of xenon into the interelectrode space, and the second is the operation mode with residual helium in the chamber and local injection of xenon directly into the compression zone. The maximum value of the electric current observed outside the MPC channel is 15 ÷ 20% of the total discharge current. Electric current vortices were discovered in the plasma stream. The amplitude of the current in the vortices reaches 50% of the total discharge current. The maximum EUV radiation power was measured in the mode of MPC operation with local xenon injection. Power in the wave range 12.2 ÷ 15.8 nm achieves up to 16 ÷ 18 kW.

Research on the delamination wear properties of the pure carbon strip at the high-sliding speed with electric current

2018 ◽  
Vol 70 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Hongjuan Yang ◽  
Lin Fu ◽  
Yanhua Liu ◽  
Weiji Qian ◽  
Bo Hu
Keyword(s):  
Electric Current ◽  
High Speed ◽  
Normal Load ◽  
Copper Wire ◽  
Electrical Current ◽  
Wear Properties ◽  
Sliding Speed ◽  
Content Type ◽  
Delamination Wear ◽  
High Speed Data

Purpose This paper aims to investigate the delamination wear properties of a carbon strip in a carbon strip rubbing against a copper wire at the high-sliding speed (380 km/h) with or without electrical current. Design/methodology/approach The friction and wear properties of a carbon strip in a carbon strip rubbing against a copper wire are tested on the high-speed wear tester whose speed can reach up to 400 km/h. The test data have been collected by the high-speed data collector. The worn surfaces of the carbon strip are observed by the scanning electron microscope. Findings It was found that there was a significant increase of the delamination wear with the decrease of the normal load when the electric current is applied. The size of the flake-like peeling also increases with the decrease of normal load. The delamination wear extends gradually from the edge of the erosion pits to the surrounding area with the decrease of the normal load. However, the delamination wear never appears in the absence of electric current. It is proposed that the decreased normal load and the big electrical current are the major causes of the delamination wear of the carbon strip. Originality value The experimental test at high-sliding speed of 380 km/h was performed for the first time, and the major cause of the delamination was discovered in this paper.

Empirical Modeling of Direct Electric Current Effect on Machining Cutting Force

2013 ◽  
Author(s):  
Elizabeth Jones ◽  
Joshua J. Jones ◽  
Laine Mears
Keyword(s):  
Electric Current ◽  
Shear Plane ◽  
Electrical Current ◽  
Empirical Modeling ◽  
Machining Process ◽  
Electroplastic Effect ◽  
Direct Electric Current ◽  
Orthogonal Machining ◽  
Machining Force ◽  
Force Reduction

Metallic materials can be made more ductile and be formed at lower forces through the application of electrical current during deformation, termed Electrically-Assisted Forming (EAF). The current provides a degree of resistive heating, but also facilitates deformation by direct electrical mechanisms (termed the electroplastic effect). It is envisioned that this approach, currently applied to bulk/sheet deformation, could also be used to reduce the flow stress in the deformation zone of the machining shear plane. The objective of this work is to study and model the effect of electric current on forces in machining in order to relate the force reduction to the current level and machining process parameters. To perform this, skiving tests and orthogonal machining tests are performed with varying electrical conditions. It is shown that application of electric current does reduce machining force by up to 60% under certain conditions.

Mobility and Energy Efficiency of Military Tactical Vehicle With Hybrid-Electric Driveline System

2014 ◽  
Author(s):  
Vladimir V. Vantsevich ◽  
Jesse R. Paldan ◽  
Jeremy P. Gray
Keyword(s):  
Mathematical Model ◽  
Eddy Current ◽  
Hybrid Electric Vehicle ◽  
Operation Mode ◽  
Planetary Gear ◽  
Electrical Current ◽  
Gear Ratio ◽  
Front Axle ◽  
Tactical Vehicle ◽  
Hybrid Electric

In this paper, a technical concept is described for a power transmitting unit to control the split of power between the drive axles of a 4×4 hybrid-electric vehicle. This new power transmitting unit uses a planetary gear set and eddy current brake to provide a continuously variable gear ratio that can be integrated into the vehicle driveline between the transfer case and front axle. The paper details the electrical and mechanical characteristics of the device, including its operation mode, its mathematical model built from the equations of the planetary gear set and eddy current brake, the optimization equation by which the device will be controlled to improve vehicle slip efficiency, as well as its torque and electrical current usage. Computer simulations are performed on a mathematical model of a 4×4 military truck using the power transmitting unit in conjunction with a series hybrid-electric configuration transmission.

Buckling and Postbuckling of Electroconducting Elastic Plates in a Magnetic Field

2002 ◽  
Author(s):  
Davresh Hasanyan ◽  
Liviu Librescu ◽  
Damodar R. Ambur
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Ferromagnetic Material ◽  
Electrical Current ◽  
Elastic Plates ◽  
Postbuckling Behavior ◽  
Field Equations ◽  
Flat Plates ◽  
Theory Of Plates ◽  
Basic Equations

The basic equations of a fully nonlinear theory of electromagnetically conducting flat plates carrying an electric current and exposed to a magnetic field of arbitrary orientation are summarized. The relevant equations have been obtained by considering that both the elastic and electromagnetic media are homogeneous and isotropic. The geometrical nonlinearities are considered in the von-Ka´rma´n sense, and the soft ferromagnetic material of the plate is assumed to feature negligible hysteretic losses. Based on the electromagnetic and elastokinetic field equations, by using the standard averaging methods, the 3-D coupled problem is reduced to an equivalent 2-D one, appropriate to the theory of plates. Having in view that the elastic structures carrying an electric current are prone to buckling, by using the presently developed theory, the associated problems of buckling and post-buckling are investigated. In this context, the problem of the electrical current inducing the buckling instability of the plate, and its influence on the postbuckling behavior are analyzed. In the same context, the problem of the natural-frequencies electrical current interaction of flat plates, as influenced by a magnetic field is also addressed.

Investigations of the physical nature of the emergence and spread of relativistic astrophysical jets

2018 ◽  
Vol 27 (10) ◽  
pp. 1844002 ◽  
Author(s):  
Vadim S. Belyaev ◽  
Anatoly P. Matafonov ◽  
Boris V. Zagreev
Keyword(s):  
Radiation Power ◽  
Physical Nature ◽  
Target Surface ◽  
Maximum Energy ◽  
Plasma Stream ◽  
Astrophysical Jets ◽  
Relativistic Jets ◽  
Proton Beams ◽  
Laser Facility ◽  
Ring Structures

A series of experiments were carried out at the TSNIIMASH laser facility “Neodym” with a radiation power of 10 TW and an intensity of [Formula: see text]–[Formula: see text][Formula: see text]W/cm2 to simulate the formation and development of astrophysical relativistic jets. It was shown that proton beams are emitted symmetrically in the forward and backward directions to the normal of the target surface. The maximum energy of fast protons and electrons was 5 and 8[Formula: see text]MeV, respectively. At energies in the 0.8–1.7[Formula: see text]MeV range, the ring structures of proton beams are clearly distinguishable with an angular divergence in the range of 3–250. The numerical magnetohydrodynamic calculations have shown that such laboratory experiments can simulate the formation of astrophysical jets with an anomalously small divergence. Moreover, such a plasma stream can form a distinct circular structure. These structures also can be explained as Alfven vortex solitons formed under the conditions of a quasi-stationary superstrong ([Formula: see text]100 MG) magnetic field spontaneously generated in laser produced plasma. It is shown that this model can be used as a model of astrophysical relativistic jets.

The Formative Phase of a Low Pressure, High Voltage Z Pinch

1972 ◽  
Vol 50 (20) ◽  
pp. 2475-2481 ◽  
Author(s):  
C. S. Maclatchy ◽  
A. J. Barnard
Keyword(s):  
Spatial Distribution ◽  
Energy Spectrum ◽  
Current Layer ◽  
Exact Nature ◽  
Axial Region ◽  
Total Discharge Current ◽  
The Face ◽  
Z Pinch ◽  
Total Discharge ◽  
A Current

The formative phase of a 40 kV Z pinch has been investigated for pressures from 10 to 80 mTorr in H2. The energy spectrum of the electrons on the axis of the vessel, the spatial distribution of the current at the face of the anode, and the total discharge current were monitored. At the initiation of the discharge, a current of electrons with energies in excess of 20 keV is observed on the axis. This observation is in contrast to the normally accepted mode of ionization in which ionization initiates at the wall. The current is observed to switch from the axial region to the wall where it forms a current layer which collapses in accordance with the snow-plough model. The exact nature of the switching mechanism is not understood. The formative phase of the pinch typically takes a few hundred nanoseconds. The observations indicate that the detailed process of current sheet collapse may be affected by the formative phase.

scholarly journals Impressed Current Anti Fouling (ICAF) to Reduce Population of Chlorella Vulgaris Cause Bio Corrosion on AH36 Steel in Marine Environment

2019 ◽  
Vol 125 ◽  
pp. 06001 ◽  
Author(s):  
Herman Pratikno ◽  
Harmin Sulistiyaning Titah ◽  
Handayanu ◽  
Gilang Rezha Mahardhika
Keyword(s):  
Atomic Absorption ◽  
Electric Current ◽  
Marine Environment ◽  
Chlorella Vulgaris ◽  
Pure Copper ◽  
Electrical Current ◽  
Cell Number ◽  
Duration Time ◽  
Impressed Current

Corrosion can cause damage to steel. One of the main causes of corrosion is biofouling. The Impressed Current Anti Fouling (ICAF) method is one way to prevent the microfouling. The purpose of the study was to calculate reduction of Chlorella Vulgaris population using a simple ICAF system. The simple ICAF reactor was operated with variation of electric current (0.3, 0.5 and 1 A) and duration time (5, 7 and 10 min). Steel of AH36 has a role as a cathode, meanwhile pure copper (Cu) was an anode. The cell number of Chlorella Vulgaris was determined using haemacytometer method. The concentration of Cu was determined using Atomic Absorption Spectrophotometers (AAS). Based on the results, the simple ICAF system showed the decreasing of Chlorella Vulgaris cell number with the highest percentage of 99.98% at electrical current of 1 A, duration time of 10 min and concentration of Cu (17.9 ± 0.07 mg/L). Meanwhile, the lowest of the cell number reduction was 97.57% at electrical current of 0.3 A, duration time of 5 min and concentration of Cu (15.52 ± 0.25 mg/L). In conclusion, ion Cu that was produced during operation simple ICAF system can reduce Chlorella Vulgaris population.

Development of Electric Current Sensor for the Device Protecting Electrical Wiring against Sparks

2016 ◽  
Vol 856 ◽  
pp. 337-342 ◽  
Author(s):  
Aleksandr Kovalyov ◽  
Sergei Soleniy ◽  
Oksana Solenaya
Keyword(s):  
Electric Current ◽  
Electrical Current ◽  
Current Sensor ◽  
Electrical Characteristics ◽  
Electric Network ◽  
Electrical Wiring

The paper is devoted to the development of electrical current sensor, comparable with one pole of protective-switching apparatus of electric network for the voltage up to 1 kV. It is defined, that variation of mass, dimensions and electrical characteristics of the sensor generates a nominal row of currents of the device, protecting from sparks.

Measurement of Void Fraction in Dispersed Bubbly Flow With Constant Electric Current Method

2012 ◽  
Author(s):  
Shin-ichiro Uesawa ◽  
Akiko Kaneko ◽  
Yutaka Abe
Keyword(s):  
Electric Current ◽  
Void Fraction ◽  
Bubbly Flow ◽  
Three Dimensional ◽  
Current Method ◽  
Electrical Current ◽  
Measurement Methods ◽  
Polarization Method ◽  
Void Fractions ◽  
Fraction Measurement

Void fraction is one of important physical values for gas-liquid two-phase flow in nuclear power plants, and it is an essential parameter for designs and performance evaluations of devices, including a core of BWR and so on. Therefore void fraction measurement with real time, high temporal resolution and high spatial resolution has been needed. In several void fraction measurement methods, electric measurement methods of void fraction can realize real-time measurement. In previous studies, conductance methods capacitance methods, wire mesh methods and tomography techniques have been studied. In the present study, we research on a constant electric current method. This method can measure void fraction with higher temporal resolution and simpler systems. In previous study, the constant electrical current method has been applied in annular flow mainly. However, the method cannot be applied to three dimensional dispersed bubbly flow. This is because void fraction is estimated by cross-section ratio of gas and liquid phases in this method. In the present study, Maxwell’s theory and polarization method are applied to calculation method of void fraction from voltage measured by constant electrical current method, and we try to measure void fraction in dispersed bubbly flow. Maxwell’s theory is a calculation of a mixture with two materials of different conductivity. The polarization method proposed in this study assumes bubbles to be dielectric bodies and void fraction is estimated by the polarization electric field of the bubbles. In the experimental results, the void fractions in the three dimensional dispersed bubbly flow can be estimated with Maxwell’s theory and the polarization method. The void fractions estimated with these methods are more accurately than the previous method. Furthermore, it is experimentally clarified that the present proposed method can follow highly temporal void fluctuations of bubbly and froth flows. In addition, effects of intervals between electrodes and structures of electrodes are experimentally investigated.

The Influence of the Temperature in Severe Wear of Copper Contact Wire/carbon Strip under Electric Current

2011 ◽  
Vol 71-78 ◽  
pp. 3653-3656
Author(s):  
Tao Ding ◽  
Guang Xiong Chen ◽  
Zeng Gang Xiong ◽  
Li Xie ◽  
Chuan Xue Wu
Keyword(s):  
Friction Coefficient ◽  
Electric Current ◽  
Experimental Tests ◽  
Electrical Current ◽  
Severe Wear ◽  
Contact Wire ◽  
Thermal Wear ◽  
Current Passage ◽  
Pin On Disc ◽  
Contact Couple

A series of experimental tests were carried out using copper contact wire rubbing against carbon strip under electric current on a pin-on-disc test. The aim to experiment can be understand the roles of the thermal wear in severe wear of copper/carbon strip under electrical current passage. During testing, the contact temperature and friction coefficient were recorded. The wear volumes of carbon strip specimens were measured. The results indicate that the temperature rise of contact couple with and without electric current is distinctly different. And the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. It can be found that the wear volumes of carbon strip samples with electric current are larger than those without electrical current. Several thermal wear tests were conducted to study the influence of the temperature on the wear of carbon strip samples. The result indicates that thermal wear, oxidation wear and abrasive wear are a main mechanism for the severe wear of carbon strip samples.

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