Joule Heat Generation by Electric Current in Nanostructures

2019 ◽  
pp. 7-1-7-14
Author(s):  
S. V. Gantsevich ◽  
V. L. Gurevich
Keyword(s):  
Electric Current ◽  
Heat Generation ◽  
Joule Heat

Simulation of the Electric Current Flow in Amorphous-Crystalline Ti2NiCu Alloy with Shape Memory Effect

2016 ◽  
Vol 845 ◽  
pp. 146-149
Author(s):  
Dmitriy S. Kuchin ◽  
Victor V. Koledov ◽  
Pavel V. Bogun ◽  
Peter V. Lega ◽  
Vedamanickam Sampath ◽  
...  
Keyword(s):  
Electric Current ◽  
Current Flow ◽  
Amorphous Matrix ◽  
Volume Fraction ◽  
Current Density Distribution ◽  
Heat Evolution ◽  
Equatorial Region ◽  
Joule Heat ◽  
Electric Pulses ◽  
Electric Current Flow

A new technique for the production of nanograined alloys from rapidly quenched amorphous ribbons by serial electric pulses has been proposed recently [1]. The present work involves a theoretical study of electric current flow in a nonhomogeneous Ti2NiCu alloy consisting of an amorphous matrix with a crystalline phase of spherical morphology embedded in it. The electric current density distribution was calculated in the vicinity of a spherical nucleus, which has an electrical resistance that is only 0.4 times that of the amorphous matrix. The calculation of Joule heat density was done in the nucleus and in the amorphous volume surrounding it. It was shown that during the current pulse the Joule heat evolution in nucleus exceeds one in equatorial region in matrix, but less than near the poles. The dependence of relative resistivity of nonhomogeneous amorphous-crystalline alloy on volume fraction of spherical crystalline nuclei was calculated

scholarly journals The Law of Entropy Increase and the Meissner Effect

Entropy ◽  
2022 ◽  
Vol 24 (1) ◽  
pp. 83
Author(s):  
Alexey Nikulov
Keyword(s):  
Electric Current ◽  
Normal State ◽  
Irreversible Process ◽  
Meissner Effect ◽  
Joule Heat ◽  
Persistent Current ◽  
Conventional Theory ◽  
Entropy Increase ◽  
The Law ◽  
Theory Of Superconductivity

The law of entropy increase postulates the existence of irreversible processes in physics: the total entropy of an isolated system can increase, but cannot decrease. The annihilation of an electric current in normal metal with the generation of Joule heat because of a non-zero resistance is a well-known example of an irreversible process. The persistent current, an undamped electric current observed in a superconductor, annihilates after the transition into the normal state. Therefore, this transition was considered as an irreversible thermodynamic process before 1933. However, if this transition is irreversible, then the Meissner effect discovered in 1933 is experimental evidence of a process reverse to the irreversible process. Belief in the law of entropy increase forced physicists to change their understanding of the superconducting transition, which is considered a phase transition after 1933. This change has resulted to the internal inconsistency of the conventional theory of superconductivity, which is created within the framework of reversible thermodynamics, but predicts Joule heating. The persistent current annihilates after the transition into the normal state with the generation of Joule heat and reappears during the return to the superconducting state according to this theory and contrary to the law of entropy increase. The success of the conventional theory of superconductivity forces us to consider the validity of belief in the law of entropy increase.

scholarly journals Electro-slag heating of parts surfaces by welding of protective coatings by the method of immersion

2019 ◽  
Vol 298 ◽  
pp. 00145
Author(s):  
Vladimir Fedyaev ◽  
Petr Osipov ◽  
Alexey Belyaev ◽  
Liliya Sirotkina
Keyword(s):  
Mathematical Model ◽  
Electric Current ◽  
Solid Body ◽  
Finite Differences ◽  
Protective Coatings ◽  
Joule Heat ◽  
Heat Released ◽  
Practical Recommendations

One of the effective methods of surfacing protective coatings on large areas, as well as the formation of permanent joints is the method of immersion (dipping) of parts into the melt. In order to increase the productivity of this method, the quality of surfacing is proposed to heat the work surfaces of the parts with an electroslag method. The rational regimes for its realization are determined by calculation. A mathematical model is proposed for heating the contacting layers of a solid body, slag and melt, taking into account the Joule heat released during the passage of an electric current. The corresponding problem is solved numerically with the help of the method of finite differences. The results are discussed, practical recommendations are presented.

scholarly journals Improved melting of latent heat storage via porous medium and uniform Joule heat generation

2020 ◽  
Vol 31 ◽  
pp. 101747 ◽  
Author(s):  
Hayder I. Mohammed ◽  
Pouyan Talebizadehsardari ◽  
Jasim M. Mahdi ◽  
Adeel Arshad ◽  
Adriano Sciacovelli ◽  
...  
Keyword(s):  
Porous Medium ◽  
Latent Heat ◽  
Heat Generation ◽  
Heat Storage ◽  
Joule Heat ◽  
Latent Heat Storage

scholarly journals Heat generation by eddy currents in a shell of superconducting bus-bars for SIS100 particle accelerator at FAIR

2017 ◽  
Vol 66 (4) ◽  
pp. 705-715 ◽  
Author(s):  
Łukasz Tomków ◽  
Stanisław Trojanowski ◽  
Marian Ciszek ◽  
Maciej Chorowski
Keyword(s):  
Optimal Design ◽  
Electric Current ◽  
Liquid Helium ◽  
Heat Generation ◽  
Eddy Currents ◽  
Superconducting Magnets ◽  
Particle Accelerator ◽  
Cryogenic System ◽  
Steel Shell ◽  
University Of Technology

Abstract Superconducting magnets in the SIS100 particle accelerator require the supply of liquid helium and electric current. Both are transported with by-pass lines designed at Wrocław University of Technology. Bus-bars used to transfer an electric current between the sections of the accelerator will be encased in a steel shell. Eddy currents are expected to appear in the shell during fast-ramp operation of magnets. Heat generation, which should be limited in any cryogenic system, will appear in the shell. In this work the amount of heat generated is assessed depending on the geometry of an assembly of the bus-bars and the shell. Numerical and analytical calculations are described. It was found that heat generation in the shell is relatively small when compared to other sources present in the accelerator and its value strongly depends on the geometry of the shell. The distribution of eddy currents and generated heat for different geometrical options are presented. Based on the results of the calculations the optimal design is proposed.

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