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The purpose of this paper is to introduce a numerical calculation method to study the uniformity of the magnetic field in a cold crucible used for directional solidification (DS) and provide information for designing a cold crucible that can induce a uniform magnetic field.

To obtain the characteristics of the magnetic field in a cold crucible and its influence on the directional solidification processing, based on experimental verification, 3‐D finite element (FE) models with different crucible configuration‐elements and power parameters were established to study the uniformity of the magnetic field in a cold crucible. In addition, different TiAl ingots were directionally solidified with different cold crucibles, and the solid/liquid (S/L) interfaced were examined to investigate the effect of the magnetic field on the macrostructure of those ingots.

The uniformity of the magnetic field in a given domain can be quantitatively analyzed by statistical methods. Numerical calculation results showed that the uniformity of the magnetic field can be improved by optimizing the crucible configuration and adopting lower frequency. Better uniformity of the magnetic field in a cold crucible is beneficial to directional solidification.

The calculation of the uniformity of the magnetic field is proposed as a method for quantitative study of the distribution characteristics of the magnetic field in a cold crucible. The relationship between the S/L interfaces of TiAl ingots and the uniformity of the magnetic field is initially characterised; additionally, techniques for improving the uniformity of the magnetic field in a cold crucible are suggested.

Aims to present recent activities in numerical modeling of turbulent transport processes in induction crucible furnace.

3D large eddy simulation (LES) method was applied for fluid flow modeling in a cylindrical container and transport of 30,000 particles was investigated with Lagrangian approach.

Particle accumulation near the side crucible boundary is determined mainly by the ρ_p/ρ ratio and according to the presented results. Particle settling velocity is of the same order as characteristic melt flow velocity. Particle concentration homogenization time depends on the internal flow regime. Separate particle tracks introduce very intensive mass exchange between the different parts of the melt in the whole volume of the crucible.

Transient simulation of particle transport together with LES fluid flow simulation gives the opportunity of accurate prediction of admixture concentartion distribution in the melt.

Heating with a low-frequency induction is a key phenomenon in a process dedicated to the treatment of nuclear wastes. This paper aims to present a step of the numerical model being developed to study this process.

A hydrodynamic model for the processing of a liquid charge consisting of a metallic phase and a dielectric one is developed based on a volume of fluid (VOF) approach coupled with electromagnetic calculations. The latter allows one to calculate the distribution of the Joule heating in the setup and radiative heat exchange inside the crucible is accounted with a surface-to-surface (S2S) model coupled with VOF.

Numerical results are compared with the measures obtained on the prototype of the process. The results are in good agreement but the model needs to be improved to consider the varying viscosity of the glass.

The usage of a S2S radiation model coupled to the VOF model is not common for studies of materials melted by electromagnetic induction. This paper demonstrates the feasibility of this approach.

Comprehensive knowledge of the complicated physical behavior of the induction furnace with cold crucible (IFCC) is required to utilize the advantages of this melting aggregate in melting and casting chemically high‐reactive materials, like titanium‐aluminides (TiAl). Practical experiences show that the overheating temperature of the melt is decisive for the quality of the cast products. Therefore, a systematic analysis of the electromagnetic and in particular, the hydrodynamic and thermal behavior of the IFCC is carried out. The examinations of the influence of the construction elements as well as the process parameters on the temperature field and finally the overheating temperature in the IFCC are performed using specifically developed numerical models. The evaluation of the numerical results is done by experimental investigations, where aluminum serves as a model melt for the experimental determination of the thermal and hydrodynamic field of the melt. The analysis of the influence of construction‐elements on the overheating temperature is focused on the design of the crucible wall and the crucible bottom, on the height‐diameter ratio of the crucible and on the axial inductor position. The inductor current, the operation frequency and the crucible filling level are found to be very important for reaching a high overheating temperature.

A small size cold crucible offers possibilities for melting various electrically conducting materials with a minimal wall contact. Such small samples can be used for express contamination analysis, preparing limited amounts of reactive alloys or experimental material analyses. Aims to present a model to follow the melting process.

The presents a numerical model in which different types of axisymmetric coil configurations are analysed.

The presented numerical model permits dynamically to follow the melting process, the high‐frequency magnetic field distribution change, the free surface and the melting front evolution, and the associated turbulent fluid dynamics. The partially solidified skin on the contact to the cold crucible walls and bottom is dynamically predicted. The segmented crucible shape is either cylindrical, hemispherical or arbitrary shaped.

The model presented within the paper permits the analysis of melting times, melt shapes, electrical efficiency and particle tracks.

Aims to present recent activities in numerical modeling of cold crucible melting process.

3D numerical analysis was used for electromagnetic problem and 3D large eddy simulation (LES) method was applied for fluid flow modeling.

The comparative modeling shows, that higher H/D ratio of the melt is more efficient when total power consumption is considered, but this advantage is held back by higher heat losses through the crucible walls. Also, calculations reveal that lower frequencies, which are energetically less effective, provide better mixing of the melt.

3D electromagnetic model, which allows to take into account non‐symmetrical distribution of Joule heat sources, together with transient LES fluid flow simulation gives the opportunity of accurate prediction of temperature distribution in the melt.

The purpose of this paper is to investigate a new type of nozzle which is free from erosion and non-contaminating the outflow metal. Cold crucible melting technique with electromagnetic induction is used to obtain reactive metal castings and produce high-quality metal powders for aerospace, automotive and medical applications. An important part of this technology is the nozzle used to pour the molten alloy through the bottom opening.

The paper uses mathematical modeling technique, previously validated on multiple similar cases, to investigate a new type of nonconsumable nozzle made of copper segments.

The design of the nozzle requires to satisfy the narrow balance between the thin solidified protective layer on the wall while avoiding the blockage of the outflow if the nozzle is frozen completely. The sensitivity of the outflow to the nozzle diameter is investigated. The AC electromagnetic force leads to high mixing rates, transitional flow structures and turbulence of the melt, contributing to the melt shape dynamics and the heat loss to walls.

The beneficial features of the cold crucible melting to purify the melt from particulate contamination are explained using the full melting and pouring cycle.

Aims to present recent activities in experimental investigations and numerical modelling of the induction cold crucible installation.

Temperature and velocity measurements using thermocouples and electromagnetic velocity probes were performed in aluminium melt which was used as a model melt. Measured temperature field and flow pattern were compared with transient 3D calculations based on large eddy simulation (LES) turbulence modelling scheme. Numerical results are in good coincidence with the experimental data.

The modelling results show that only 3D transient LES is able to model correctly these heat and mass transfer processes.

It is revealed that transient 3D modelling provides a universal tool for simulating convective heat and mass transfer processes in the entire melt influenced by large scale instabilities in the recirculating flows, which contain several main vortexes of the mean flow.

The purpose of this paper is obtaining the optimal parameters of induction heating and melting systems by use of the new programs ELectro-Thermal Analysis (ELTA) 8.0 and Induction Crucible Furnace (ICF) to improve a quality of final products.

Simulation of continuous through heating prior a drawing through the draw plate is realized by an optimization procedure. Additional application of ELTA 8.0 “Heating of Wire” reveals the relationship between power, time and thermal profile of load during heating. Rational variants of ICFs for melting processes are obtained using several step-by-step iterations.

ELTA 8.0 program permits to optimize the continuous heating of copper, steel, titanium and other wires. ICF ELTA program was used at the initial stage of the development of new technological processes and the ICFs. This program provides a preliminary evaluation of an induction melting process and system before the use of more sophisticated 2D or 3D programs. Results of optimization allowed to find a rational decision of an induction system, the required parameters of a refractory and a power supply. Non-conductive and graphite crucibles of the furnace were compared from electrical and economical points of view.

Fast calculation of ELTA programs allows the designer to provide the required temperature distribution in a cross section and along the part to control the real-time processes of heating and melting.

This paper aims to report on a vitrification process based on direct induction that has been developed by the French Atomic Energy Commission (CEA, France). This process is characterized by currents directly induced inside the molten glass and by the cooling of all the crucible walls. In addition, a mechanical stirring device is used to homogenize the molten glass. This paper presents a global modelling of coupled phenomena that take place within the glass bath.

Electromagnetic, thermal and hydrodynamic phenomena are modelled. The aim of this study is to develop strategy of coupled modelling between these aspects. The thermohydrodynamic calculations are achieved with the Fluent software (distributed by Fluent France) and the electromagnetic aspects are solved by the OPHELIE program based on integral methods (developed in EPM laboratory).

Two configurations are considered: the first deals with thermal convection in an unstirred bath and the second takes into account the mechanical stirring.

The main limitation is that repartition of the Joule power density within the molten glass is supposed to be not perturbed by the intrusive elements like the thermocouples or the stirrer. This assumption allows us to perform only axisymmetric calculations of induction effect.

This paper present different strategy of coupling the thermohydrodynamic and direct induction phenomena taken place in the molten glass.