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19 results on '"Sviželová, Jana"'

3. Preparation of Rotor Geometry for Setting up Numerical Model of Flow in Refining Ladle †.

Author

Manoch, Lukáš, Socha, Ladislav, Sviželová, Jana, Gryc, Karel, and Mohamed, Adnan

Subjects
PETROLEUM refineries, PETROLEUM refining, COMPUTATIONAL fluid dynamics, GEOMETRY, MATHEMATICS
Abstract

Foundry Degassing Units (FDU) are used for refining aluminum alloys. For an ideal refining process using an FDU unit, it is necessary to select several parameters, which are linked to each other. For a rotary impeller, we searched for several parameters, such as its optimal shape, speed in the liquid alloy, and distance from the bottom of the refining ladle, where the aforementioned parameters contribute to the overall wear and life of the rotor and, consequently, of the rotor shaft. The Computational Fluid Dynamics (CFD) method can be used to determine the above-mentioned parameters. This paper describes the particular steps of preparation of rotor geometry for the subsequent setting up of the basic numerical model. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Quality Assessment of Aluminium Castings Using Computed Tomography †.

Author

Pinta, Martin, Socha, Ladislav, Gryc, Karel, Sviželová, Jana, and Koza, Kamil

Subjects
ALUMINUM, COMPUTER simulation, COMPUTED tomography, DIE castings, POROSITY
Abstract

The article deals with the use of computed tomography, an advanced method for evaluating the quality of aluminium castings. Casting quality is a key factor in ensuring safety and reliability in industrial applications. Computed tomography is a comprehensive method allowing a three-dimensional, high-resolution view of the internal structure of materials. The main focus of this paper is the study of BRACKET REAR aluminium castings, manufactured in two-piece moulds using a high-pressure die-casting technology. In this paper, four castings have been analysed which are produced in one cycle. The focus is on the problem of porosity and open stagnation in the castings. A numerical simulation has also been used to illustrate the occurrence of porosity, which can be used to determine both the occurrence of porosity and the occurrence of unfilled volume. The experimental part of the paper describes the methods used to evaluate the BRACKET REAR castings. The numerical simulation was performed in ProCAST 18.0 to determine the occurrence of porosity in the castings under study. The evaluation of computed tomography was performed in myVGL 3.0 2023 software to analyse the internal defects in the castings. The evaluation focused on assessing internal defects and their subsequent effect on the functionality of the final casting. [ABSTRACT FROM AUTHOR]

Published
2024
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5. Comparison of Degassing Efficiency on a Foundry Degassing Unit Using Different Rotor Types.

Author

Kolínský, Jan, Prášil, Tomáš, Socha, Ladislav, Sviželová, Jana, Gryc, Karel, Häusler, Josef, and Dvořák, Martin

Subjects
ROTORS, GAS flow, FOUNDRIES, NOBLE gases
Abstract

The present paper describes a comparison of the efficiency of different types of rotors used in the refining of aluminium melt at a foundry degassing unit (FDU). Physical modelling was used to obtain data for six different rotor types under defined experimental conditions. In order to evaluate the data from the physical model, an evaluation method based on the interpolation of degassing curves was developed in such a way that the resulting characteristic can be expressed by a single parameter. Using the new methodology, the datasets were replaced by a single dimensionless parameter, a, which characterizes the rotor performance at a given gas flow rate. Based on the comparison of these performance parameters, it was possible to mutually compare the rotor efficiency depending on the selected conditions. The comparison is also demonstrated on the expected degassing time to a certain required concentration. Based on the physical model results, the study found that rotor D had the highest degassing efficiency, followed by rotors F and A. Rotors B and E had similar efficiency at a flow rate of 17 Nl·min−1. However, rotor B showed better efficiency at higher inert gas flow rates (19 and 21 Nl·min−1), while rotor E showed better efficiency at lower flow rates (13 and 15 Nl·min−1). [ABSTRACT FROM AUTHOR]

Published
2024
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9. Prediction of defects of ductile iron casting by numerical simulation

Author

Sviželová, Jana, Socha, Ladislav, Gryc, Karel, Chmiel, Miroslav, Brathová, Michaela, Kučerová, Ludmila, Jirková, Hana, and Jeníček, Štěpán

Subjects
tvárná litina, ductile iron, casting defects, vady odlitku, numerical simulation, MAGMASOFT, filling and solidification, numerická simulace, plnění a tuhnutí
Abstract

V průběhu odlévání odlitků z tvárné litiny mohou vznikat podmínky příznivé pro vznik vnitřních vad v odlitcích. Přítomnost těchto vad může být pro daný odlitek fatální a společně s dalšími okolnostmi vést k jeho likvidaci. Proto je potřeba odhalit přítomnost vad, pokud možno ještě ve fázi návrhu odlitku. K tomuto účelu lze využít numerické simulace, které jsou v dnešní době běžně používaným nástrojem k predikci vad. Tato práce popisuje proceduru numerického modelování odlévání a tuhnutí odlitku z tvárné litiny, určeného pro energetický průmysl. Cílem numerických simulací byla predikce odlévání, tuhnutí a napěťových stavů s cílem ověřit adekvátnost navržené technologie výroby. Numerické simulace odhalily mírné nedostatky v technologii výroby, jež by mohly při neočekávané změně procesních podmínek vest ke vzniku vad. Tyto nedostatky se týkaly zejména vtokové soustavy, nálitkování odliku a náchylnosti ke vzniku trhlin. Na základě simulací byla navržena opatření pro eliminaci rizik spojených se vznikem diskutovaných vad, jež budou zakomponována do technologie výroby. PING Junior 2021 is organized with the support of funds for specific university research project SVK1-2021-008 and ERDF "Research of additive technologies for future applications in the machinery industry - RTI plus" (No. CZ.02.1.01/0.0/0.0/18_069/0010040).

Published
2021

10. Optimization of ductile iron casting production based on numerical simulation

Author

Socha, Ladislav, Gryc, Karel, Sviželová, Jana, Chmiel, Miroslav, Brathová, Michael, Kučerová, Ludmila, Jirková, Hana, and Jeníček, Štěpán

Subjects
tvárná litina, ductile iron, casting defects, vady odlitku, numerical simulation, MAGMASOFT, filling and solidification, numerická simulace, plnění a tuhnutí
Abstract

V rámci výzkumu byly provedeny numerické simulace ve výpočetním SW MAGMASOFT, zaměřené na optimalizaci odlévání a tuhnutí daného typu odlitku, určeného pro lodní průmysl. Tento článek prezentuje výsledky numerických simulací společně s návrhem změn v technologii výroby, vedoucích ke zvýšení kvality odlitku. Z výsledků simulací nebyly zjištěny závažné nedostatky navržené technologie. Z hlediska optimalizace plnění však byla doporučena úprava tvaru zářezů pro zamezení rozstřiku kovu. Pro dosažení struktury bez vnitřních vad se doporučuje optimalizace nálitkování odlitku a mírná úprava tvaru pro eliminaci rizika tvorby porezity a prasklin. PING Junior 2021 is organized with the support of funds for specific university research project SVK1-2021-008 and ERDF "Research of additive technologies for future applications in the machinery industry - RTI plus" (No. CZ.02.1.01/0.0/0.0/18_069/0010040).

Published
2021

16. Numerical modelling of metal melt refining process in ladle with rotating impeller and breakwaters

Author

Sviželová, Jana, Tkadlečková, Markéta, Michalek, Karel, Walek, Josef, Saternus, Mariola, Pieprzyca, Jacek, and Merder, Tomasz

Subjects
rotating impeller, aluminium, refining, numerical modelling, degassing
Abstract

The paper describes research and development of aluminium melt refining technology in a ladle with rotating impeller and breakwaters using numerical modelling of a finite volume/element method. The theoretical aspects of refining technology are outlined. The design of the numerical model is described and discussed. The differences between real process conditions and numerical model limitations are mentioned. Based on the hypothesis and the results of numerical modelling, the most appropriate setting of the numerical model is recommended. Also, the possibilities of monitoring of degassing are explained. The results of numerical modelling allow to improve the refining technology of metal melts and to control the final quality under different boundary conditions, such as rotating speed, shape and position of rotating impeller, breakwaters and intensity of inert gas blowing through the impeller. Web of Science 64 2 664 659

Published
2019

17. Evaluation of approaches of numerical modelling of solidification of continuously cast steel billets

Author

Tkadlečková, Markéta, Michalek, Karel, Strouhalová, Michaela, Sviželová, Jana, Saternus, Mariola, Pieprzyca, Jacek, and Merder, Tomasz

Subjects
porosity, temperature field, steelmaking, numerical modelling, continuous casting, steel
Abstract

The paper evaluates two approaches of numerical modelling of solidification of continuously cast steel billets by finite element method, namely by the numerical modelling under the Steady-State Thermal Conditions, and by the numerical modelling with the Traveling Boundary Conditions. In the paper, the 3D drawing of the geometry, the preparation of computational mesh, the definition of boundary conditions and also the definition of thermo-physical properties of materials in relation to the expected results are discussed. The effect of thermo-physical properties on the computation of central porosity in billet is also mentioned. In conclusion, the advantages and disadvantages of two described approaches are listed and the direction of the next research in the prediction of temperature field in continuously cast billets is also outlined. Web of Science 63 2 1008 1003

Published
2018

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