Wyniki wyszukiwania - Biblioteka Nauki

1

Higher-order model of electromagnetic valve for control of liquid flow

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Mach F. , Karban P. , Doležel I.

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tom Vol. 12

21--29

EN

An electromagnetic valve for control of flow of electrically non-conductive liquids is proposed and modeled. The device contains only one movable part (a cylindrical plunger) whose movement is controlled by a secondary magnetic circuit with a high-parameter permanent magnet and current in the field coil. The paper presents its mathematical model that is solved numerically. For computations we used our own code Agros2D based on a fully adaptive higher-order finite element method. The static characteristics of the device are calculated using a modified version of the Eggshell method in order to avoid undesirable peaks and oscillations. The principal results are evaluated and discussed.

2

Model of magnetic gun with respecting eddy currents

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Leubner K. , Doležel I. , Laga R.

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tom Vol. 13

12--20

EN

A sophisticated mathematical model of the magnetic gun is presented and solved numerically. The model consists of three strongly non-linear and non-stationary differential equations describing the time-dependent distribution of magnetic field in the device, current in the field circuit and movement of the projectile. The numerical solution is carried out in the application Agros2D based on a fully adaptive higher-order finite element method. The results are processed in Wolfram Mathematica. The methodology is illustrated with an example and selected results are compared with experiment.

3

3D analysis of coupled quasi-stationary electromagnetic and non-stationary temperature fields in non-magnetic inductively heated charge

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Barglik J. , Doležel I. , Šolin P. , Urlych B.

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tom z. 97

9-16

EN

The paper deals with the mathematical and computer modelling of induction heating of non-ferromagnetic prismatic bodies by inductors of general configuration. The task is formulated as a 3D, quasi- or hard-coupled electromagnetic-temperature problem. Distribution of the eddy currents and the corresponding specific Joule losses within the heated body is determined from the Fredholm integral equation of the second kind and the consequent non-stationary temperature field by the finite difference method. The suggested algorithm respects the dependence of all material characteristics on the temperature. The theoretical analysis is supplemented with an illustrative example and discussion of the results.

PL

W pracy przedstawiono matematyczny i komputerowy model nagrzewania indukcyjnego wsadów nieferromagnetycznych pryzmatycznych we wzbudniku bezrdzeniowym o dowolnym kształcie. Rozkład prądów wirowych i gęstości objętościowej mocy czynnej wydzielonej we wsadzie wyznaczono w oparciu o równanie całkowe Fredholma II rzędu, a niestacjonarne pole temperaturowe metodą różnic skończonych. Proponowany algorytm uwzględnia sprzężenie obu pól i zależność parametrów materiałowych od temperatury. Analiza teoretyczna jest uzupełniona o przykład obliczeniowy i dyskusję wyników.

4

Induction Heating of Cylindrical Billets in Magnetic Field Produced by Permanent Magnets: Simulation and Experiments

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Doležel I. , Mach F. , Karban P. , Musálek L.

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tom R. 89, nr 3a

250--252

EN

A complete overview of results is presented concerning induction heating of nonmagnetic cylindrical billets in magnetic field produced by permanent magnets. The authors proposed and modelled two possible ways of the process. The billet either rotates inside a system of appropriately arranged static permanent magnets or a ring containing such magnets rotates around an unmoving billet. Both arrangements were modelled numerically using fully adaptive higher-order finite element method and some results were verified by experiments on a physical model built in our lab.

PL

W pracy opisano rezultaty modelowania procesu nagrzewania indukcyjnego kęsów aluminiowych w polu magnetycznym wytwarzanym przez magnesy stałe. Autorzy proponują i modelują dwa warianty technologii. Kęs może być obracany wewnątrz zestawu odpowiednio ustawionych magnesów lub pierścień magnesów jest obracany względem nieruchomego kęsa. Oba warianty były symulowane przy pomocy w pełni adaptacyjnej metody elementów skończonych wyższych rzędów. Niektóre wyniki symulacji porównano z modelem fizycznym zbudowanym przez autorów.