Liquid metal flow under traveling magnetic field-solidification simulation and pulsating flow analysis

Non steady applied magnetic field impact on a liquid metal has good prospects for industry. For a better understanding of heat and mass transfer processes under these circumstances, numerical simulations are needed. A combination of finite elements and volumes methods was used to calculate the flow and solidification of liquid metal under electromagnetic influence. Validation of numerical results was carried out by means of measuring with ultrasound Doppler velocimetry technique, as well as with neutron radiography snapshots of the position and shape of the solid/liquid interface. As a result of the first part of the work, a numerical model of electromagnetic stirring and solidification was developed and validated. This model could be an effective tool for analyzing the electromagnetic stirring during the solidification process. In the second part, the dependences of the velocity pulsation amplitude and the melt velocity maximum value on the magnetic field pulsation frequency are obtained. The ability of the pulsating force to develop higher values of the liquid metal velocity at a frequency close to the MHD resonance was found numerically. The obtained characteristics give a more detailed description of the electrically conductive liquid behaviour under action of pulsating traveling magnetic field. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Numerical Simulation of Double Side Traveling Magnetic Field Electromagnetic Stirrer

The description of the electromagnetic stirring model by traveling magnetic field is given. The coupled solution of the electromagnetic, hydrodynamic problem is performed in a two-dimensional formulation by the finite element method. The behavior of particles in turbulent flow is taken into account and described by Stokes drag law. As a result, the resulting spatial distribution of the impurity is uniform in height of the container, with the existing "dead zones".В представленной работе приводится описание модели электромагнитного перемешивателя бегущим магнитным полем. Совместное решение электромагнитной, гидродинамической задачи выполнено в двухмерной постановке методом конечных элементов. Поведение примесей в турбулентном потоке учтено и описывается законом Стокса. В результате полученное пространственное распределения примеси имеет равномерный характер по высоте емкости, при имеющихся «мертвых зонах»

Numerical calculation of large-sized objects induction heating

The paper describes a numerical procedure for modeling induction heating of large objects. A coupled calculation of the electromagnetic and thermal fields is performed by the finite element method in a three-dimensional formulation. The setting of the computational mesh is described. The results of numerical calculations are demonstrated. © Published under licence by IOP Publishing Ltd.This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation, project No. 075-11-2019-028

The influence of traveling magnetic field inductor asymmetric power supply on the liquid metal flow

In modern times, exposure to a liquid metal by a travelling magnetic field is widely applied. There are laboratory studies on the processes of stirring and crystallization under the action of a traveling magnetic field. However, in the majority of studies it is assumed that the inductor power supply of the linear induction machine is carried out by a symmetrical three-phase system of currents with an equal phase shift, which, in some cases, is not quite correct. To approximate the model to real operating conditions, a numerical simulation of the magnetic field and the flow of liquid metal was carried out when supplied from a power source of symmetric three-phase voltage. The distortion of magnetic field, which, in turn, causes an nonuniform distribution of forces and the flow of a liquid metal, is shown. Evaluation of asymmetrical effect on the liquid metal flow was carried out by means of finite element method. That effect is caused by different coefficients of mutual coils induction of the linear induction machine, which is confirmed by experimental data. © Published under licence by IOP Publishing Ltd.Russian Foundation for Basic Research, RFBR: 17-48-590539 r aUral Federal University, UrFUThe work of Institute of Continuous Media Mechanics team is supporting by the RFBR grant 17-48-590539 r a and the work of Ural Federal University team is supporting by Act 211 Government of the Russian Federation, contract 02.A03.21.0006

Stirring flow of liquid metal generating by low-frequency modulated traveling magnetic field in rectangular cell

In the present work the influence of low frequency modulation of a travelling magnetic field (TMF) on a process of generation of electro-vortex flows in electrically conducting media are numerically and experimentally investigated. The measurements are carried out on a low melting temperature GaZnSn alloy by means of Ultrasonic Doppler Velocimetry. For numerical simulation, Comsol Multiphysics software was used. The dependencies of average and pulsating Reynolds numbers on the magnitude of electromagnetic impact and two modes of low frequency modulation are considered. A positive influence of reversed TMF modulations on the stirring process is determined. In particular the formation of a small-scale vortex structure in the main volume of liquid media. © Published under licence by IOP Publishing Ltd.Russian Foundation for Basic Research, RFBR: 17-48-590539_r_aUral Federal University, UrFUThe work of Institute of Continuous Media Mechanics team is supported by the RFBR grant 17-48-590539_r_a and the work of Ural Federal University team is supported by Act 211 Government of the Russian Federation, contract є 02.A03.21.0006

Flux Density Measurement at Technological Application Induction Device

In this paper, the induction measurement technique of electrotechnological installations by Hall sensors with subsequent digitization of the signal and processing on a PC is considered for. The composition of the equipment used for the measurement is presented, a series of experiments for measurement the magnetic induction was conducted and compared with the calculated characteristics.В работе рассматривается способ измерения индукции электротехнологических установок датчиками Холла с последующей оцифровкой сигнала и обработкой на ПК. Приводится состав оборудования, использованного для измерения, проведена серия опытов по измерению магнитной индукции на холостом ходу, произведено сравнение с расчетными характеристиками

Synthesis, bonding properties and ether activation reactivity of cyclobutadienyl-ligated hybrid uranocenes

A series of hybrid uranocenes consisting of uranium(iv) sandwiched between cyclobutadienyl (Cb) and cyclo-octatetraenyl (COT) ligands has been synthesized, structurally characterized and studied computationally. The dimetallic species [(η4-Cb′′′′)(η8-COT)U(μ:η2:η8-COT)U(THF)(η4-Cb′′′′)] (1) forms concomitantly with, and can be separated from, monometallic [(η4-Cb′′′′)U(THF)(η8-COT)] (2) (Cb′′′′ = 1,2,3,4-tetrakis(trimethylsilyl)cyclobutadienyl, COT = cyclo-octatetraenyl). In toluene solution at room temperature,1dissociates into2and the unsolvated uranocene [(η4-Cb′′′′)U(η8-COT)] (3). By applying a high vacuum, both1and2can be converted directly into3. Using bulky silyl substituents on the COT ligand allowed isolation of base-free [(η4-Cb′′′′)U{η8-1,4-(iPr3Si)2C8H6}] (4), with compounds3and4being new members of the bis(annulene) family of actinocenes and the first to contain a cyclobutadienyl ligand. Computational studies show that the bonding in the hybrid uranocenes3and4has non-negligible covalency. New insight into actinocene bonding is provided by the complementary interactions of the different ligands with uranium, whereby the 6d orbitals interact most strongly with the cyclobutadienyl ligand and the 5f orbitals do so with the COT ligands. The redox-neutral activation of diethyl ether by [(η4-Cb′′′′)U(η8-C8H8)] is also described and represents a uranium-cyclobutadienyl cooperative process, potentially forming the basis of further small-molecule activation chemistry

Liquid Metal Flow Under Traveling Magnetic Field—Solidification Simulation and Pulsating Flow Analysis

Non steady applied magnetic field impact on a liquid metal has good prospects for industry. For a better understanding of heat and mass transfer processes under these circumstances, numerical simulations are needed. A combination of finite elements and volumes methods was used to calculate the flow and solidification of liquid metal under electromagnetic influence. Validation of numerical results was carried out by means of measuring with ultrasound Doppler velocimetry technique, as well as with neutron radiography snapshots of the position and shape of the solid/liquid interface. As a result of the first part of the work, a numerical model of electromagnetic stirring and solidification was developed and validated. This model could be an effective tool for analyzing the electromagnetic stirring during the solidification process. In the second part, the dependences of the velocity pulsation amplitude and the melt velocity maximum value on the magnetic field pulsation frequency are obtained. The ability of the pulsating force to develop higher values of the liquid metal velocity at a frequency close to the MHD resonance was found numerically. The obtained characteristics give a more detailed description of the electrically conductive liquid behaviour under action of pulsating traveling magnetic field