Interaction Between Solid Copper Jets and Powerful Electrical Current Pulses

2010 ◽  
Vol 78 (2) ◽  
Author(s):  
Patrik Appelgren ◽  
Torgny E. Carlsson ◽  
Andreas Helte ◽  
Tomas Hurtig ◽  
Anders Larsson ◽  
...  

The interaction between a solid copper jet and an electric current pulse is studied. Copper jets that were created by a shaped-charge device were passed through an electrode configuration consisting of two aluminum plates with a separation distance of 150 mm. The electrodes were connected to a pulsed-power supply delivering a current pulse with amplitudes up to 250 kA. The current and voltages were measured, providing data on energy deposition in the jet and electrode contact region, and flash X-ray diagnostics were used to depict the jet during and after electrification. The shape of, and the velocity distributions along, the jet has been used to estimate the correlation between the jet mass flow through the electrodes and the electrical energy deposition. On average, 2.8 kJ/g was deposited in the jet and electrode region, which is sufficient to bring the jet up to the boiling point. A model based on the assumption of a homogenous current flow through the jet between the electrodes underestimates the energy deposition and the jet resistance by a factor 5 compared with the experiments, indicating a more complex current flow through the jet. The experimental results indicate the following mechanism for the enhancement of jet breakup. When electrified, the natural-formed necks in the jet are subjected to a higher current density compared with other parts of the jet. The higher current density results in a stronger heating and a stronger magnetic pinch force. Eventually, the jet material in the neck is evaporated and explodes electrically, resulting in a radial ejection of vaporized jet material.

2009 ◽  
Vol 77 (1) ◽  
Author(s):  
Patrik Appelgren ◽  
Melker Skoglund ◽  
Patrik Lundberg ◽  
Lars Westerling ◽  
Anders Larsson ◽  
...  

In this paper we present a study of the interaction between an electric current pulse and a solid copper jet. Experiments were performed using a dedicated pulsed power supply delivering a current pulse of such amplitude, rise time, and duration that the jet is efficiently affected. The copper jet was created by using a shaped charge warhead. An electrode configuration consisting of two aluminum plates with a separation distance of 150 mm was used. The discharge current pulse and the voltages at the capacitors and at the electrodes were measured to obtain data on energy deposition in and the resistance of the jet and electrode contact region. X-ray diagnostics were used to radiograph the jet, and by analyzing the radiograph, the degree of disruption of the electrified jet could be obtained. It was found that a current pulse with an amplitude of 200–250 kA and a rise time of 16 μs could strongly enhance the natural fragmentation of the jet. In this case, the initial electric energy was 100 kJ and about 90% of the electric energy was deposited in the jet and electrodes. At the exit of the electrode region, the jet fragments formed rings with a radial velocity of up to 200 m/s, depending on the initial electric energy in the pulsed power supply.


Author(s):  
Ari Ramadhani

Abstract - Automatic system have grown widespread across all sector so do water heater. Traditionally, heating water is done by utilizing fire as heat source. As the growing of technology, the heating process could be done by manipulating electrical energy by convert it to heat. Electrical energy is flown to a metal rod that contact directly with the water which increase the water temperature. On some case, appropiate water temperature is needed. Altough, a thermometer is needed to read the actual temperature as a feedback value for the system and a system that can control the electricity current flow through the heater that the heat produced is linear to the current flow. With implementing microcontroller as a process node for generating PWM signal, this problem can be solved. Also, Labview is needed as an interface for monitoring and bursting an output which have been processed by Proportional, Integral, and Devivative (PID) controller to producing accurate and stable heat. Based on the results of testing, the system is able to provide a rapid response to any changes that occur, both changes in set-point and changes in water temperature (actual value). Another test is done by comparing the temperature value detected by the temperature sensor in this device with an external digital thermometer placed in the same place, and from some of the tests the temperature value detected by the temperature sensor in this device has a difference of ± 0.19 ℃ with a digital thermometer. Keyword : Water Heater, Thermometer, Microcontroller, LabView, PID.


Geophysics ◽  
1988 ◽  
Vol 53 (11) ◽  
pp. 1445-1452 ◽  
Author(s):  
J. O. Parra

A leak in a geomembrane lined impoundment or landfill has a characteristic electrical response. I simulate the waste material, the liner, and the soil under the liner by infinite horizontal layers and express the secondary potential for a leak in the geomembrane liner in terms of a three‐layer medium Green’s function and the unknown current density distribution at the leak. The area of the leak is sufficiently small for the leak current density to be essentially uniform. I add the primary potential associated with a leak‐free liner to the secondary potential to form an integral equation and derive a general expression for the current density at the boundary between the waste material and the liner. From the expression for the current density, I determine the current flow through the leak by assuming that the total current distribution flows vertically across a finite region of the infinite, thin liner layer. This finite region has the same surface area as does the waste disposal site or landfill. My analysis implies that the current density is the most sensitive variable affecting the magnitude of current flow through the leak and the amplitude of the leak anomaly response. Multiple circular leaks in the thin resistive liner are included in the analysis. The potential anomaly of a leak is a localized response which is capable of providing a useful means for detecting and locating such leaks accurately in large waste disposal sites or landfills. Excellent agreement between experimental and model data shows my general solution is accurate in predicting leak signatures and suggests the solution may be useful to model field data acquired in geomembrane lined impoundments or landfills.


2017 ◽  
Author(s):  
Weichao Wu ◽  
Chun Xu ◽  
Chaorun Si ◽  
Tian Xue

The influences of dislocation magnification due to plastic deformation and solute atoms concentration on the electroplastic effect were investigated. It is found that the dislocation magnification due to plastic deformation will enhance the electroplastic effect. The electroplastic effect of Al-Cu alloy was enhanced with the increase of plastic deformation and current density. Moreover, the solute atoms concentration has a great effect on the electroplastic effect. The influence of electrical current pulse on Portevin-Le Chatelier (PLC) effect of Al-Cu alloy is also reported.


2020 ◽  
Vol 6 (8(77)) ◽  
pp. 21-23
Author(s):  
S.N. Sarmasov ◽  
R.Sh. Rahimov ◽  
T.Sh. Abdullayev

The effect of oxygen adsorption on the conductivity of PbTe films is studied. Pn junctions based on PbTe films are photosensitive in the IR spectral region with a maximum photosensitivity of 𝜆𝑚𝑎𝑥 microns. The tunneling mechanism of current flow through the pn junction is shown.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2542
Author(s):  
Karol Ulatowski ◽  
Radosław Jeżak ◽  
Paweł Sobieszuk

(1) The generation of nanobubbles by electrolysis is an interesting method of using electrical energy to form bubble nuclei, effectively creating a multiphase system. For every process, the effectiveness of nanobubble generation by electrolysis depends on various process parameters that impact should be determined. (2) In this work, the electrolytic generation of hydrogen and oxygen bubbles was performed in a self-built setup, in which a Nafion membrane separated two chambers. The generation of bubbles of both gases was investigated using Box–Behnken experimental design. Three independent variables were salt concentration, current density, and electrolysis time, while the dependent variables were Sauter diameters of generated bubbles. An ANOVA analysis and multivariate regression were carried out to propose a statistical and power model of nanobubble size as a process parameter function. (3) The generation of bubbles of hydrogen and oxygen by electrolysis showed that different factors or their combinations determine their size. The results presented in this work proved to be complementary to previous works reported in the literature. (4) The Sauter diameter of bubbles increases with salt concentration and stays constant with increasing current density in investigated range. The proposed correlations allow the Sauter diameters of nanobubbles generated during electrolysis to be predicted.


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