International Journal of Applied Electromagnetics and Mechanics - Volume 53, issue S1

Article Type: Other

DOI: 10.3233/JAE-162233

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S1-S2, 2017

Authors: Marioni, L. | Alves, J. | Bay, F. | Hachem, E.

Article Type: Research Article

Abstract: Electromagnetic stirring (EMS) is widely used to increase the efficiency in continuous casting process of steel. In particular, in-mould applications (M-EMS) allow decreasing the free surface fluctuation, controlling the velocity field and decreasing the turbulence of the flow. Since laboratory-scale tests are not fully representative of the process and industrial measurements are both expensive and difficult to carry out, numerical simulation is a strong tool to study and optimize these electromagnetic applications in steel industry. These simulations cannot fully model the process of its multiphysical nature and the simulation of all the phenomena involved would lead to huge computational costs, …which is one of the main limits in the current situation. For this reason, this work aims at starting searching a coupling algorithm which could guarantee both computational efficiency and accuracy of the final results. Show more

Keywords: Continuous casting, electromagnetic stirring, mesh adaptation, finite elements

DOI: 10.3233/JAE-162245

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S3-S10, 2017

Authors: Shoihet, A. | Frechter, Y. | Berdichevsky, V. | Shvartsas, M. | Rabinovici, R.

Article Type: Research Article

Abstract: Levitation melting is one of the unique techniques in containerless melting experiments and solidification of materials for processing under high magnetic fields. In recent years this technique has spread to other research areas of metallurgy and it is currently used in applications like alloy preparation, metal purification and grain refinement. Usually, levitation melting is achieved by using coaxial two-section coils. The bottom and the upper sections carry currents in opposite directions. Different apparatus coil configurations and electrical parameters, like current frequency and amplitude, have a direct effect on the free surface shape of the molten charge. It is crucial …to know the final molten metal shape, as a prediction tool of levitation melting success, during design procedure. By means of developed iterative model, the equilibrium shape of levitated molten metal is found. This model takes into considerations a balance of hydrostatic, surface tension and magnetic pressures at the metal interface. The predicted shapes of the metal droplet as well as its position inside the inductor are correlate with that of the experimental data. Show more

Keywords: Electromagnetic levitation, shape control, induced eddy currents, levitation melting

DOI: 10.3233/JAE-162234

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S11-S19, 2017

Authors: Lundström, Fredrik | Frogner, Kenneth | Wiberg, Oscar | Cedell, Tord | Andersson, Mats

Article Type: Research Article

Abstract: Carbon fiber reinforced plastics, CFRP, are attractive materials not only because of their strength and stiffness but also because of their electrical conductivity and high thermal conductivity and diffusivity. One application where induction heating of CFRP is particularly interesting is tools for fast thermal cycling, beneficial in many industrial processes, for example in composite manufacturing. The electrical properties make it possible to heat with induction and the high thermal conductivity allows fast heat equalization. In order to control inducting heating of CFRP it is desirable to know the electrical and thermal properties of the composite. This work presents developed experimental …methods that are used in an investigation of how the thermal and electrical properties of CFRP structures are affected by the fiber properties and composite structure. The experiments and simulations show that fiber type and fiber volume fraction are of great importance for the electrical and thermal properties. The relation between fiber volume fraction and equivalent resistivity is nonlinear and the experiments indicate that a fiber volume fraction exceeding 60% is necessary to achieve a fairly isotropic resistivity and uniform induction heating pattern. Show more

Keywords: Carbon fiber composites, CFRP, induction heating, uniform heating, isotropy

DOI: 10.3233/JAE-162235

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S21-S30, 2017

Authors: Pavlovs, Sergejs | Jakovics, Andris | Baake, Egbert | Sushkovs, Vadims

Article Type: Research Article

Abstract: The paper presents transient distributions of physical fields, computed with LES (Large Eddy Simulation ), for turbulent bubbles flow through electrically conductive liquid in rectangle bubble reactor (RBR ) or cylindrical bubble reactor (CBR ), which are placed in external uniform horizontal or vertical magnetic field. Experimentally verified (without magnetic field) Euler-Euler approach, realized with ANSYS Fluent Magnetohydrodynamic (MHD ) module , is used for multiphase flow, when continuous phase is electrically conductive liquid (water-like liquid or Wood -metal) and dispersed phase is gas (air or nitrogen) bubbles.

Keywords: Numerical simulation, bubble reactor, multiphase MHD-flow, Euler-Euler approach, LES, uniform magnetic field

DOI: 10.3233/JAE-162236

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S31-S41, 2017

Authors: Beckstein, Pascal | Galindo, Vladimir | Gerbeth, Gunter

Article Type: Research Article

Abstract: With the Ribbon Growth on Substrate (RGS) technology, a new crystallization technique is available that allows controlled high crystallization rate production of silicon wafers and advanced metal-silicide alloys. Compared to other casting methods, such as e.g. directional solidification, the RGS process allows better crystallization control, high volume manufacturing and high material yield due to its continuous, substrate-driven design. Insights from modelling the characteristic melt flow in the casting frame are very desirable. To address this demand, we are developing a new numerical tool based on OpenFOAM [1] which can be utilized to simulate the free-surface dynamics of the melt …flow under the influence of alternating electromagnetic fields. The underlying multi-physical model involves three-dimensional hydrodynamic and magnetodynamic effects and their interaction. Show more

Keywords: Ribbon Growth on Substrate, numerical simulation, coupled multi-physics, free-surface flow, eddy-currents

DOI: 10.3233/JAE-162237

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S43-S51, 2017

Authors: Ruggiero, M. Rosaria | Geninatti Crich, Simonetta | Sieni, Elisabetta | Sgarbossa, Paolo | Cavallari, E. | Stefania, Rachele | Dughiero, Fabrizio | Aime, Silvio

Article Type: Research Article

Abstract: Recently, nanoscale stimuli-responsive devices have received much attention thanks to their potential to limit the cytotoxic effect of the therapeutic treatment at the diseased tissue. Among different physical triggers, large alternating magnetic fields enable the conversion of magnetic energy into heat by using magnetic nanoparticles that generate localized hyperthermia, named Magneto Fluid Hyperthermia (MFH). This methodology can be exploited for cancer therapy or/and thermally activated drug release. The small size iron oxide nanoparticles (Fe-NPs), such as SPIO (small iron oxide particles) and USPIO (ultra-small iron oxide particles), currently used for this application have many limitations due to their 1) …high intratumor concentration needed due to the low heating power 2) short particle blood-half-life, 3) non-specific distribution, 4) low internalization efficiency. For these reasons many efforts are necessary to make magneto fluid particle hyperthermia (MFH) a competitive tumor therapy for clinical applications. New iron oxide nanoparticles, coated with oleate, with a diameter of 5-18 nm, have been prepared by co-precipitation and incorporated into PLGA-NPs (PLGA=Poly(lactic-co-glycolic acid) in order to improve their biocompatibility and ``in vivo '' stability. Moreover, PLGA-NPs have been loaded with both NPs-Fe and antitumor drugs (Paclitaxel, PTX), an anticancer hydrophobic drug used in the treatment of ovarian and breast cancer, to perform MFH triggered drug release. The PTX and Fe-NPs loaded nanoparticles may be considered as an effective anticancer drug delivery system for Imaging-guided hyperthermic treatment of tumors. Show more

Keywords: Magnetic fluid hyperthermia, iron oxide particles, poly lactic and glycolic acid, nuclear magnetic resonance, paclitaxel

DOI: 10.3233/JAE-162246

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S53-S60, 2017

Authors: Spitans, Sergejs | Baake, Egbert | Jakovics, Andris | Franz, Henrik

Article Type: Research Article

Abstract: In this paper, a drip- and leakage-free approach for electromagnetic (EM) levitation melting of metallic samples in horizontal and orthogonal two-frequency fields is studied further. Numerical simulation is used to design an experimental furnace for a stable levitation melting of aluminum samples with increased weight. The scale-up of the method is validated by experiments with aluminum (Al) samples up to 0.5 kg.

Keywords: Electromagnetic levitation, liquid metal, free surface, numerical simulation

DOI: 10.3233/JAE-162238

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S61-S66, 2017

Authors: Terzijska, Džulia | Lüdtke, Ulrich

Article Type: Research Article

Abstract: Lorentz force velocimetry (LFV) [1] is a contactless measurement technique, which uses the principle of induction to analyze physical properties of moving and electrically conducting media. We report a systematic numerical optimization procedure with finite element (FEM) simulation to improve the measurement quality of LFV for weakly conducting media. The force can be increased by optimizing the primary magnetic field created by a magnet system. We use magnetic dipoles as field sources. Analytic and numerical studies of the influence of single magnetic dipoles on the conducting medium have been investigated [2-4]. The optimization of different dipole configurations with a high …number of dipoles is new and presents the next step in the development of Lorentz force flowmeters for weakly conducting fluids for industrial application. We study and optimize the orientation of dipoles with the FEM software PROMETHEUS and develop an optimization method. The resulting optimized dipoles exhibit characteristic orientations, which are point symmetric with respect to the center of the geometric setup so that the magnitudes of the vector fields wind themselves like a spiral around the pipe. Show more

Keywords: Gradient-ascent, Lorentz force, low magnetic Reynolds number, magnetic dipoles, optimization

DOI: 10.3233/JAE-162239

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S67-S78, 2017

Authors: Schubotz, S. | Nacke, B.

Article Type: Research Article

Abstract: In high performance induction heating systems, the coil often has a short lifetime as a result of high power density generated in some areas. The cause of life reduction is often because the cooling effect of the coolant is not sufficient or the heat is not dissipated adequately. This is usually due to a poor heat transfer between the cooling water and the coil. The sizing of the cooling system and the coil have a high impact on the heat transfer and therefore also on service life. Generally, the system parameters affected by this dimensioning are the cooling water temperature, …cooling water flow (velocity) and pressure. In this paper, a method is presented which allows a research of the influences by these different parameters on the heat transfer coefficient. For this purpose, a water-cooled, cylindrical copper part is heated by induction and the heat transfer to the coolant is examined. Considering that, a concept has been developed and analyzed by means of a 2D model. This is followed by the implementation of the model using an experimental setup, where an individual adjustment of the three cooling parameters has been realized and also its impacts on the heat transfer coefficient. Show more

Keywords: Induction heating, convective heat transfer coefficient, lifetime of coils

DOI: 10.3233/JAE-162240

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S79-S88, 2017

Authors: Kichigin, V. | Nacke, B. | Poznyak, I.

Article Type: Research Article

Abstract: A distinctive feature of induction furnaces with cold crucible is the skull melting without introducing any impurities in the melt and overheating of the melt over 3000°C at air. Therefore the technology of induction melting in cold crucible is suitable for high temperature synthesis of oxide materials. This paper describes a new technology for continuous melting and pouring of oxide melts. A new type of cold crucible with two chambers is used for this application. In the first chamber the charged oxide is melted and transferred via a barrier to the second chamber where the oxide is superheated before pouring …over a discharging hole. During the transfer of the melted oxide from the melting zone into the superheating zone the transport of non-melted oxide particles has to be avoided. This transport is mainly influenced by the hydrodynamics of the melt flow and the temperature field during melting and pouring. Numerical simulation is used to investigate the heat and mass transfer during the melting and pouring processes in the cold crucible furnace. Both forced and free convections are taken into account in the simulation. Apart from the melt flow inside the cold crucible special attention is also paid to the behavior of the pouring stream. The numerical results are compared with experimental data of melting and pouring experiments in the skull melting installation at the Institute of Electrotechnology. The paper presents a description of the cold crucible setup, the results of the numerical simulation and comparison of them with experimental data. Show more

Keywords: Skull melting, oxide melting, oxide pouring

DOI: 10.3233/JAE-162247

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S89-S94, 2017

Authors: Djambazov, G. | Bojarevics, V. | Pericleous, K. | Forzan, M.

Article Type: Research Article

Abstract: Solar grade silicon production is an energy intensive and harmful to the environment process. Yet 40% of this valuable product material is lost into sawdust (kerf loss) during wafering. The kerf waste from Fixed Abrasive Sawing of PV silicon wafers is pelletized and then remelted in an induction furnace. The furnace has a square cross-section quartz crucible, surrounded by graphite susceptors and heated by an induction coil that enables directional solidification of the new ingot. Top and bottom `pancake' coils provide additional temperature control. Once melted, silicon becomes electrically conductive and subject to stirring by induction. To recycle the silicon, …particulate impurities (due to the sawing, condensed silicon oxides or carbides) need to be removed. Flow control and the electromagnetic Leenov-Kolin force are used to expel particulates, through a novel dual frequency induction scheme. Three-dimensional, multi-physics numerical modelling captures the electromagnetic, fluid-flow and heat-transfer effects in this process. The presented results show it is possible to retain the impurity particles on the sides of the solidified ingot where they can be sliced off and removed. Show more

Keywords: Silicon recycling, electromagnetic separation, dual frequency induction melting

DOI: 10.3233/JAE-162248

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S95-S102, 2017

Authors: Rognin, Etienne | Rossa, Guillaume Barba | Brun, Patrice | Sauvage, Emilien | Lacombe, Jacques

Article Type: Research Article

Abstract: In this article, we report 3D numerical simulations of highly conductive non-magnetic particles dispersed in a moderately conductive matrix, subject to an AC magnetic field in a range of several hundred kHz. We address the issue of the scaling of current loops and heating power with respect to the volume fraction of the dispersed phase. Simulations are performed in two steps. First, a static electric potential gradient is imposed between two opposite faces of the simulation domain and an effective conductivity is computed in good agreement with percolation models. Second, the particles are constrained in a spherical sub-region and an …AC magnetic field is imposed at the boundary of the domain. For small volume fractions, the induced Joule power is in good agreement with an analytical model of dilute dispersions. As the volume fraction increases, wider current loops form, until the percolation threshold is reached. Then the induced power in the spherical aggregate is well described by the power induced in an equivalent sphere with a volume-fraction-dependent conductivity. Show more

Keywords: Particles, eddy currents, heating power, effective conductivity

DOI: 10.3233/JAE-162241

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S103-S110, 2017

Authors: Fehling, T. | Steinberg, T. | Baake, E.

Article Type: Research Article

Abstract: In our modern society hydrogen is an important alternative energy source for current and future applications in fuel cells as well as coolants or hydrogenation of coal. To achieve an environmentally compatible production of hydrogen, another method of thermal decomposition, is discovered. In this process methane is injected with an orifice at the bottom of an bubble column reactor that is filled with liquid tin. While rising up in the reactor, the methane bubbles do a chemical decomposition reaction into hydrogen and carbon, which is depending on the tin temperature. In this article a numerical model for the methane bubble …flow inside the tin melt is described. For that case residence times and flow structures are discovered depending on different heating systems of the melt - heating coil and electromagnetic field. In the following studies different inlets types as well as installations like packed beds are discovered to view their influence on higher residence times and efficiency of the reaction. Show more

Keywords: Numerical simulation, bubble dynamics, thermal decomposition, magnetohydrodynamics

DOI: 10.3233/JAE-162242

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S111-S120, 2017

Authors: Kozuka, T. | Sigit, W.P. | Fukuda, S. | Iihoshi, C. | Kawahara, M.

Article Type: Research Article

Abstract: Metal anodizing process is now widely applied to not only usual commercial products but also advanced materials like a photo-catalyst or some nano-materials. In these applications, micro-pore or nano-pore structure in the anodized oxide film, e.g. pore arrangement or straightness, is considered to be important to improve the performance of electric devices etc. In this research, in order to obtain good arrangement and straightness and control of pore size, strong magnetic field and strong electric field imposition during anodization are conducted for Al and Ti under intense electric field and intense magnetic field imposition. Strong electric field can control the …pore size and its distribution. Strong magnetic field can promote the metal substitution reaction and it also increase the metal anodizing. Furthermore, magnetic field has the possibility of ordering the pore arrangement in the anodized film. Show more

DOI: 10.3233/JAE-162243

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S121-S128, 2017

Authors: Lope, I. | Carretero, C. | Acero, J. | Serrano, J. | Burdío, J.M.

Article Type: Research Article

Abstract: Cost-effective solutions for domestic induction heating appliances have become a priority in recent years. With this purpose, the implementation of Printed Circuit Board (PCB) inductors has entailed important research efforts. A proper litz structure is essential to achieve high-efficiency PCB inductors. This structure requires routing the traces by using vias in a double layer PCB to obtain the appropriate transposition pattern. In this paper, the optimal number of vias has been analyzed to minimize the power losses in the coil. This analysis has been carried out based on numerical calculations whose results have been experimentally verified.

Keywords: Home appliances, induction heating, magnetic devices

DOI: 10.3233/JAE-162244

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S129-S137, 2017

Authors: Di Barba, P. | Mognaschi, M.E. | Lowther, D.A. | Dughiero, F. | Forzan, M. | Lupi, S. | Sieni, E.

Article Type: Research Article

Abstract: In the paper, a benchmark in the area of induction heating is presented in order to test methods and codes of field analysis in a comparative way. In particular, the transient thermal analysis of a magnetic steel cylindrical billet is considered: the coupled-field problem is characterized by a twofold non linearity, i.e. the dependence of magnetic permeability on both field strength and temperature.

Keywords: Induction heating, multiphysics problem, magnetic-steel billet, finite element analysis, benchmark problem

DOI: 10.3233/JAE-162249

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. S1, pp. S139-S149, 2017