Papers by Victor Demidovich
Faculty of Electrical Engineering, University of West Bohemia, 2021
This article deals with the findings of researches and development of the theory for non-crucible... more This article deals with the findings of researches and development of the theory for non-crucible induction melting of non-magnetic billets with due account of the MHD effect.
In 1935, Professor V.P. Vologdin and engineer B.N. Romanov conducted successful experiments on th... more In 1935, Professor V.P. Vologdin and engineer B.N. Romanov conducted successful experiments on the use of high frequency currents (HFC) for induction surface hardening. The overwhelming success of this technology at tank factories during the Great Patriotic War was highly appreciated by the government of the USSR and in 1947 the All-Union Research Institute of High Frequency Currents (VNIITVCH) was created. The article discusses the organization of scientific research at the institute and at the department of Saint. Petersburg State Electrotechnical University (LETI), the features of the organization of the educational process, the achievements of recent years and promising areas of research on metal processing in an alternating electromagnetic field.
COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2020
Purpose The purpose of this study is research and development of the magnetohydrodynamics (MHD)-v... more Purpose The purpose of this study is research and development of the magnetohydrodynamics (MHD)-vortex technology. Design/methodology/approach The main instruments of research are mathematical modeling. For mathematical modeling used numerical and analytical both methods. For verification was made small copy of facility with forming of vortex in rotating magnetic field. Findings The design and manufacture of the industrial unit for melting small metal waste in a gas-fired smelt furnace has been completed. Originality/value Here shows new algorithm for engineering calculation of arc induction systems with take into account longitudinal edge effect and discrete distribution of current layers. Also shows verification of numerical results. Presented new MHD-technology for forming vortex in electromagnetic field.
Elektrichestvo, 2019
The article presents approaches to modeling physical processes in an MHD device using the researc... more The article presents approaches to modeling physical processes in an MHD device using the research and development of an MHD-rotating device, namely, an analytic mathematical model of an arc induction machine and a numerical model of MHD processes based on the coupling of electromagnetic and hydrodynamic problems taking into account a two-phase fluent domain. The results of calculations and analysis of the MHD-rotator are presented. Research and development of industrial plants for the smelting of small metal chips in a gas melting furnace was carried out.
Elektrichestvo, 2021
Development of an electrical calculation method plays the leading role in simulating induction de... more Development of an electrical calculation method plays the leading role in simulating induction devices. In modeling electrical devices and complexes, it is often necessary to simultaneously solve both chain and field problems, i.e., to deal with both lumped and distributed parameters. The article considers the method of integral equations for induction systems with non-magnetic and ferromagnetic loading, which is based on the theory of long-range action. The method’s key statement is that the field at any point is determined as the sum of the fields produced by all sources, including primary and secondary ones. Another finite element method is based on the theory of short-range action, which describes the electromagnetic wave propagation from point to point, its refraction and reflection at the boundaries of media. The article substantiates the development of a combined method based on using the method of integral equations for calculating the input parameters of inductors (an exter...
Èlektričestvo, May 24, 2024
COUPLED VI : proceedings of the VI International Conference on Computational Methods for Coupled Problems in Science and Engineering, 2015
RpEEE, Mar 1, 1985
In the most general model of a plasma its kinetic description is based on statistics of a multipa... more In the most general model of a plasma its kinetic description is based on statistics of a multiparticle system, which can be treated as a liquid with temperature-dependent thermal conductivity, electrical conductivity, and viscosity. The flow of such a liquid in an induction plasmatron is described accordingly, in the approximation of an equilibrium plasma. Simulation of the plasmatron performance involves calculation of the heat and mass transfer, heat sources and ponderomotive forces being obtained from the solution to the corresponding Maxwell equations, and calculation of the electromagnetic field. The electromagnetic problem can be solved by two basic methods, taking into consideration that the intricate current density distribution and the nonstationary boundaries of the conduction region are not a priori known. The first method is based on long-range action and Ampere's law. The corresponding Fredholm integral equations of the second kind need to be solved for the conduction region only. The second method is based on short-range action and mathematical description by a second-order differential equation, solvable by the algorithm of finite differences. Both methods have been combined so that the advantage of each is utilized in the proper sequence.
Metallurgist, Jun 3, 2024
2022 22nd International Symposium on Electrical Apparatus and Technologies (SIELA)
New approach of designing and control of induction heat treatment installations of pipes with uti... more New approach of designing and control of induction heat treatment installations of pipes with utilizing of numerical models is developed. Models include two- dimensional simulation of coupling electromagnetic and temperature fields in cylindrical systems for processing of pipes. Also, thermal and structural tension during heating and cooling of pipes are simulated. These data allow defining structure, hardness, the size of grain and other properties of the pipes. They allow optimizing design and a choice of equipment, a heat treatment mode for achievement of the maximum quality and minimization of energy consumption. The developed models were used not only for the design of induction heat treatment systems of pipes and rolls, but also for a digital control of these complexe
2022 Conference of Russian Young Researchers in Electrical and Electronic Engineering (ElConRus)
the article describes the development of a numerical model of an inductor and a graphite crucible... more the article describes the development of a numerical model of an inductor and a graphite crucible for an induction vacuum furnace, followed by a physical experiment - bringing the vacuum furnace to its operating temperature. A comparison of the numerical and physical experiment is carried out.
COUPLED VII : proceedings of the VII International Conference on Computational Methods for Coupled Problems in Science and Engineering, 2017
Computer modeling is necessary part of design new induction heating and melting devices [1]. One ... more Computer modeling is necessary part of design new induction heating and melting devices [1]. One of the complicated technologies when it is necessary to simulate coupled electromagnetic, temperature and magnetohydrodynamic fields is heating and melting of titanium alloys in the alternating electromagnetic field. Thermal processing of titanium alloys in the inductor has some features that it is necessary to take into account on the designing of the advanced technology and equipment. Low thermal conductivity and high temperature losses at the surface result in maximum temperature inside of the billet that could under appropriate conditions exceed melting point. In this way it is possible to obtain liquid phase of titanium alloy inside of the billet and protect it from the contact with surrounding atmosphere. To get this it is necessary to choose the right regime of processing, frequency of current, power and thermal conditions. At the same time precise heating with very strong execution of the temperature profile during the heating time are essential for thermal processing of titanium alloys in this technology [2]. Mathematical model comprising computation of electromagnetic, temperature, MHD fields after getting melt zone and dynamic of its growth was developed. The calculation of the melting process has been carried out by the method "enthalpy-porosity" with application of models of turbulent currents k-ω SST in a non-static setting. Electromagnetic forces and heat sources have been defined by solving a harmonic task by the method of finite elements on a vector magnetic potential in the system "inductor-load" for each iteration of the hydrodynamic task. Experiments confirmed need in simulation of MHD fields to receive good coincidence. Using of the developed models for simulation of electromagnetic processing billets make it easy to develop and implement optimal heat processing systems for the crucibleless induction melting of titanium alloys.The calculations on the basis of the model and the analysis of physical processes with non-crucible melting of titanium alloys have also been carried out.
Proceedings of the VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016), 2016
The metal stress-strain state simulation needs high precision computations. The use of any simpli... more The metal stress-strain state simulation needs high precision computations. The use of any simplifying assumptions, such as the plane section hypothesis, the deformable material relative compressibility, uniform temperature distribution over the cross and longitudinal sections of the strip, etc. reduces the computation accuracy of strain and stress at the nodes. Standard programs often use such assumptions. It is acceptable for solving the routine problems. For the manufacture of critical elements such assumptions can lead to undesirable serious consequences. Modeling of the metal forming processes by using the finite element method gives a more accurate solution of the problem. However, the solutions require to solve a linear equations system of high dimensionality. The coefficient matrix is sparse, namely it consists of mainly zero elements, randomly scattered. This leads to considerable computation time for solution methods. In general, the number of arithmetic operations is proportional to the cube of the system's order. In this paper, we propose to increase the computational efficiency analysis through the use of the high-sparse matrix properties. In this case computer time will be proportional to the system order to the 1.2 power. The proposed solution SLAE comprises sparse matrix methods, which include techniques for optimal ordering of matrix rows and columns by using the criterion of the rows in order to increase the first non-zero elements number. This paper shows the application of the computation method for the process of the Belleville spring upset. Belleville springs can be classified as critical elements. One of its possible applications is the rail joint. Unlike conventional parts the elastic elements are characterized by the presence of large deformation under loads. The main factor that determines the service properties of the elastic element is the amount of strain energy that it can be accumulated. Accumulation and dispersing of the Belleville springs strain energy is directly depends to the relation of the meridian cross-section size and the spring working area. The establishment of this dependence is necessary for its rational design.
2017 IEEE II International Conference on Control in Technical Systems (CTS), 2017
A single-point temperature control system is proposed and investigated in a continuous multi-sect... more A single-point temperature control system is proposed and investigated in a continuous multi-section induction furnace to control the temperature of the metal load leaving the furnace. The furnace consists of at least three sections. The temperature is measured at a fixed point along the length of the second section on the surface of the workpiece and compared with the set temperature. The power of the second section is adjusted to maintain the desired temperature at a fixed point, which ensures the necessary temperature of the metal part at the exit of the furnace. For linear thermo-technical thin bodies, the position of the point and the value of the temperature in it can be determined analytically. Such a control system can be used for heating steel bars in a continuous modular induction heater.
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Papers by Victor Demidovich