Boris Mikhailovich

Ben-Gurion University of the Negev | bgu

Small-scale turbulence measurements in liquid metals are generally conducted using potential difference probes (PDPs). However, the use of PDPs in alternating magnetic field-driven flows is limited as the driving magnetic field (DMF) induces a noise signal, which cannot be separated from the turbulence signal using a filtering algorithm that does n...

A compact Liquid Lithium Target (LiLiT) has been operating at SARAF for several years with beam power of several kW (1.9-2.5 MeV, up to 2 mA). When bombarding the lithium with low energy protons neutrons are generated. The neutron source, mainly used for nuclear astrophysics research, was decommissioned in 2016 towards an upgraded model - with poss...

In the present report, we discuss the possibility of optimization of amplitude- and frequency-modulated traveling magnetic field (AFM TMF) excited in the melt by a standard inductor for the intensification of heat and mass transfer at the out-of-furnace processing in the ladle-furnace. On the basis of theoretical analysis of electrodynamic processe...

The possibility of optimization of parameters of amplitude and frequency modulated rotating magnetic field (AFM RMF) acting on the copper wall of a mold with a square cross-section aimed at an increase of the efficiency of electromagnetic impact on the mold in the process of continuous casting of a steel billet has been theoretically substantiated.

The limits of the axisymmetric ideal inductor approach and the low magnetic Reynolds number (Rem) approach are demonstrated for the case study of a flow driven by a rotating magnetic field induced by an explicit-pole non-ideal inductor. These effects are studied for an intermediate range of the magnetic Reynolds number 0.1 ≤ Rem ≤ 1. It is shown th...

Traveling magnetic field is one of effective tools for controlling phase change processes in metals. A better understanding of electromagnetic impact in such applications can help to improve and simplify technological processes. In this paper, numerical and experimental study of the electromagnetic force generated by traveling magnetic field and it...

In recent decades, many phase change processes in metals have been optimized using traveling magnetic fields due to a better understanding of their electromagnetic impact in such applications. In this paper, numerical and experimental study of the effect of traveling magnetic field on the solidification process was evaluated. A three-dimensional nu...

The rotating magnetic field was used to improve the heat transfer in liquid metal targets exposed to high heat fluxes. Semi-analytical approximate solutions for the rotating magnetic field and for the flow field have been developed and used in parametric study and optimization of the inductor design. Additionally, the rotating magnetic field was co...

Electromagnetic methods for controlling and optimization of melting process are applied both in the laboratory conditions and in industrial processes at least within past several decades. At that, usage of rotating and traveling magnetic fields was realized based on alternating or direct current electromagnetic facilities, or on permanent magnets s...

In this paper, horizontal solidification of gallium in a rectangular cavity was studied both experimentally and numerically. Two three-dimensional (3D) numerical models related to different numerical approaches were built. The first is a single-domain (SD) model based on the volume-of-fluid (VOF) method. This model also takes into account the prese...

The behavior of azimuthal and radial velocity components of transient and free decaying rotating MHD flow in an annular gap of rectangular cross-section in an axial magnetic field has been studied. Experimental values of the velocity components of the flow were measured using a conductive anemometric system. Analysis of mean and oscillating charact...

The behavior of azimuthal and radial velocity components of transient and free decaying rotating MHD flow in an annular gap of rectangular cross-section in an axial magnetic field has been studied. Experimental values of the velocity components of the flow were measured using a conductive anemometric system. Analysis of mean and oscillating charact...

The structure formation of ingots crystallizing from the melt takes place near the crystallization front in boundary layers (namely, in the hydrodynamic boundary layer whose thickness is determined by the melt stirring intensity and temperature and by concentration layers in the case of alloy crystallization), and depends on heat and diffusion flux...

We consider a problem of spectral analysis of signals from electromagnetic sensors operating in a turbulent MHD flow generated by rotating and traveling magnetic fields, which create a strong electromagnetic noise. Using a wavelet-based technique for cross-correlation signal analysis and filtration, we show that at frequencies lower than the freque...

Magnetohydrodynamic liquid metal flow in a cylindrical vessel under the action of a system of rotating permanent magnets is examined. The described system allows to create various hydrodynamic structures and control their behaviour in a flexible way. Numerical three-dimensional modelling of the flow is carried out in an induction-free approximation...

Gallium melting in an orthogonal container under the impact of a magnetic field was studied. The main goal of the work was the numerical modeling and study of solid–liquid interface behavior and exploration of the possibility to control its dynamics using a magnetic system. The container comprised heated and cooled side faces with preset temperatur...

Liquid metal magnetohydrodynamic flow driven by a system of rotating permanent magnets in a container of orthogonal cross-section has been studied. The main objective of the work is to research the impact of magnetic forcing parameters (magnetic field value, magnets arrangement, and angular velocity of their rotation) on the generated hydrodynamic...

Liquid metal MHD flow initiated by a system of rotating permanent magnets in rectangular cavity has been investigated. We examine the impact of influential magnetic forcing parameters on the produced hydrodynamic structures in the cavity. The spin-up modes and steady-state flow regimes have been simulated in 3D numerical model and verified expe...

The problem of the stability of turbulent flows of liquid metal in a cylindrical cavity against small velocity disturbances under the action of a rotating magnetic field (RMF) has been studied. The flow is considered in the induction-free approximation using the 'external' friction model. A system of dimensionless equations is examined in cylindric...

Gallium melting in a rectangular container with a heated side face has been investigated. The focus of the research is the advancement of the numerical model to 3D status taking into consideration thermal vari-ations of medium properties and the presence of mushy zone, and the model experimental verification using known data and new data obtained o...

Results of experimental study of rotating turbulent liquid metal MHD flow in an annular gap bounded by electrically conducting coaxial cylindrical walls and insulating top and bottom walls are presented. The flow is generated by electromagnetic body forces caused by a radial electric field and by an axial magnetic field. Velocity components of the...

Melt flow in helical channels of inductive and conductive pumps is studied in the induction-free approximation using an "external" friction model and a helical coordinate system. Radial flow profiles are computed.

Purpose The purpose of this paper is to determine technological potential of using multi‐frequency electromagnetic fields for the optimization of induction heating process. Design/methodology/approach The aim of the research is achieved by using phase‐modulated current feeding the solenoid that excites the magnetic field. In this case, the magneti...

Results of experimental measurements of the azimuthal velocity component of an electrically conducting fluid rotating flow in an annular cylindrical cavity under the action of azimuthal electromagnetic force generated by the interaction of a radial electrical field with an axial magnetic field are presented. The behaviour of mean velocity and fluct...

A method of multi-frequency induction heating using frequency-modulated electric current in a heater-solenoid is proposed. Electrodynamic and thermal problems are formulated and solved. Spectral characteristics of currents in a heated cylindrical body are evaluated, and temperature dependencies for sinusoidal and frequency-modulated currents are pr...

MHD processes in melts arising under the action of a superposition of two frequency-modulated or harmonic rotating magnetic fields are described in the induction-free approximation using the "external" friction model. The results of "hot" experiments performed with 1080 steel and "cold" experiments performed with an InGaSn eutectic alloy, which mod...

Angular velocities distribution along the vertical axis was studied on a cold model of the liquid core of a continuous steel ingot of circular cross-section. Melt rotation in a harmonic and amplitude-modulated RMF was investigated. The features of the obtained angular velocity profile are interpreted on the basis of "external" friction model in the...

In the presented paper we describe the results of the experimental study of a liquid metal flow in a low-temperature model of a continuous casting facility equipped with two electromagnetic stirrers (EMS). The characteristics of turbulent melt flows in such facilities are computed on the basis of a semi-empirical model of "external" friction taking...

We substantiate the use of a two-parametric semi-empirical model of axisymmetric flow of a conducting fluid under the action of a rotating magnetic field in the approximation of flow quasi-beltramization. On the basis of experimental data obtained both by the authors of the present paper and by other researchers, the values of empirical parameters...

The effciency of technological processes of producing metals and alloys, continuous ingots and castings of ferrous and non­ferrous metals is mainly determined by the intensity of heat and mass transfer in the liquid phase. To increase the latter, various methods are used, including electromagnetic ones. Most electromagnetic methods are based on the...

Experimental studies of the effect of constant magnetic field on the process of mean velocity profile stabilization in a wake behind a bluff body are described. To interpret the obtained results, a theoretical model is proposed explaining the scheme of wave-mean flow interaction. We assume that the stabilization process is based on the injection of...

A possible mechanism of the stabilization of the turbulent wake behind a bluff body in the presence of an external magnetic field is discussed. A special role is attributed to the mechanism of energy exchange between the mean flow and the turbulent fluctuations by means of inertial waves. Figs 2, Refs 13.

In the atmospheric boundary layer there exist groups of roll vortices contributing considerably to the momentum transfer, motion properties, etc. There are data pointing to an important role of such vortices in the formation of such a dangerous extreme weather event (EWE) as a tornado. It is known that helical turbulence mode is the cause of the si...

The effect of a rotating magnetic field (RMF) on the parameters of inertial waves propagating in an arbitrary direction in a quasi-solid-state rotating conductive fluid is studied in the induction-free approximation. It is shown that, with increasing flux density of the magnetic field, the most power-intensive portion of the wave packet is focused...

The effect of a rotating magnetic field on frequency characteristics ofinertial waves arising in a quasi-solid-state core of an azimuthal flow of an electroconductive fluid in a cylindrical vessel has been studied. It is shown that some of the previously obtained experimental results can be explained by the mechanism of interaction of the alternati...

Results of experimental measurements of the azimuthal velocity component of a rotating flow of a conducting fluid in an annular cylindrical cavity under the action of azimuthal electromagnetic force generated at the interaction of a radial electric field with an axial magnetic field are presented. The obtained data are analyzed and compared with co...