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Your search keyword '"Geza, V."' showing total 17 results
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17 results on '"Geza, V."'

8. Modelling of liquid metal stirring induced by four counter-rotating permanent magnets

Author

Dzelme, V., Scepanskis, M., Geza, V., Jakovics, A., and Sarma, M.

Subjects
Physics::Fluid Dynamics
Abstract

In this work, the stirring of liquid gallium in a rectangular crucible induced by four counter-rotating permanent magnets is investigated numerically. The mean velocity and turbulence kinetic energy for different distances of the magnets from the vessel with liquid metal and the magnet rotation rate are investigated. The flow is modeled using two turbulence models - detached eddy simulation and k-ω shear stress transport - and compared with experimental results obtained using the dynamic neutron radiography method. Numerical results show qualitative agreement with experiment. The simulation results evidence that the applied turbulence models predict the velocity and the turbulence kinetic energy equally well. It is also shown that in this system the characteristic turbulence kinetic energy is proportional to the square of the characteristic velocity magnitude.

Published
2016

9. Continuous melting and pouring of an aluminum oxide based melt with cold crucible

Author

Nacke, B, Kichigin, V, Geza, V, Poznyak, I, and ETAY, Jacqueline

Subjects
[SPI] Engineering Sciences [physics], oxide melting, cold crucible melting, Electromagnetic melting, continuous pouring, skull melting
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

Published
2015

13. A Special-Purpose Electronic Computer for Simulating and Processing Functions of Finite Homogeneous Markov Chains

Author

FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO, Bukharaev,R. G., Geza,V. I., FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO, Bukharaev,R. G., and Geza,V. I.

Abstract

The paper discusses the results of designing a special purpose computer for simulating functions of finite Markov chains when an algorithm for simulation is used. A list of problems which can be solved by this computer is given. (Author), Edited trans. from Avtomatika i Vychislitelnaya Tekhnika (USSR) p169-172 1971, by W. W. Kennedy.

Published
1972

15. Numerical modelling of surface waves generated by low frequency electromagnetic field for silicon refinement process

Author

Geza, V, Vencels, J, Zageris, G, and Pavlovs, S

Abstract

One of the most perspective methods to produce SoG-Si is refinement via metallurgical route. The most critical part of this route is refinement from boron and phosphorus, therefore, approach under development will address this problem. An approach of creating surface waves on silicon melt's surface is proposed in order to enlarge its area and accelerate removal of boron via chemical reactions and evaporation of phosphorus. A two dimensional numerical model is created which include coupling of electromagnetic and fluid dynamic simulations with free surface dynamics. First results show behaviour similar to experimental results from literature.

Published
2018

16. Thermal conductivity of disperse insulation materials and their mixtures

Author

Geza, V, Jakovics, A, Gendelis, S, Usilonoks, I, and Timofejevs, J

Abstract

Development of new, more efficient thermal insulation materials is a key to reduction of heat losses and contribution to greenhouse gas emissions. Two innovative materials developed at Thermeko LLC are Izoprok and Izopearl. This research is devoted to experimental study of thermal insulation properties of both materials as well as their mixture. Results show that mixture of 40% Izoprok and 60% of Izopearl has lower thermal conductivity than pure materials. In this work, material thermal conductivity dependence temperature is also measured. Novel modelling approach is used to model spatial distribution of disperse insulation material. Computational fluid dynamics approach is also used to estimate role of different heat transfer phenomena in such porous mixture. Modelling results show that thermal convection plays small role in heat transfer despite large fraction of air within material pores.

Published
2017

17. [Epidemiological and hygienic importance of HBs-antigen screening].

Author

Zoltan G, Nandor H, Zsuzsanna K, Zsuzsanna P, Eva N, Artur F, and Geza V

Subjects
Alcoholism immunology, Blood Donors, Gastrointestinal Diseases immunology, Hepatitis A immunology, Humans, Hungary, Mass Screening, Mental Disorders immunology, Hepatitis B Antigens isolation & purification
Published
1975

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