This paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element.
W pracy przedstawiono wyniki symulacji komputerowej koaksjalnego magnetokumulacyjnego generatora prądu (MGP). Badania symulacyjne przeprowadzono dla różnych wartości średnicy wewnętrznej, długości i prędkości odkształcania elementu MGP.
EN
The results of computer simulation of the coaxial magnetocumulative current generator (MGP) were presented in this paper. The simulation tests were carried out for different values of internal diameter, length and speed of the deformation of an MGP element.
A ferromagnetic object, located in the Earth’s magnetic field, changes its distribution. Through measuring such disturbances, one can locate the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, and its task is to eliminate the disturbances in the distribution of the Earth’s magnetic field. A thin walled elliptical shell, made of ferromagnetic material, is examined as the object model. There are coils, placed inside the shell, and their task is to generate a magnetic field, which is eliminating the effect, the shell is making on the distribution of the Earth’s magnetic field in the surrounding area. Such a procedure is called magnetic masking and the winding used for this purpose is called the masking winding. The possibility of building the masking windings for the ferromagnetic elliptical shell, situated in a transverse magnetic field respectively to its major axis, is also examined. The solution of Maxwell’s equations, which are describing the magnetic field distribution caused by the ferromagnetic shell presence in the Earth’s magnetic field, is found. Furthermore, the ability of selecting coils, which are eliminating the perturbations of the magnetic field outside the shell completely, is proven.
A ferromagnetic object, located in the Earth’s magnetic field, changes the distribution of that field. By measuring such disturbances it is possible to detect the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, which function is to eliminate the disturbances in the distribution of the Earth’s magnetic field. A thin walled ellipsoidal shell made of ferromagnetic material are examined as the object model. Coils are placed inside the shell and their function is to generate a magnetic field, which eliminates the effect the shell makes on the distribution of the Earth’s magnetic field in the surrounding area. Such a procedure is called magnetic masking and the winding used for this purpose is called the masking winding. The possibility of building the masking windings for the ferromagnetic ellipsoidal shell, situated in a magnetic field transverse in relation to its major axis, is also examined. Masking of a thin-walled ellipsoidal ferromagnetic object located in the longitudinal magnetic field is described in the article [1]. Investigating the possibility of masking of objects in a transverse magnetic field presented in this article will allow for a comprehensive assessment of a possibility of masking thin walled ferromagnetic objects of elongated ellipsoidal shape. The solution of Maxwell’s equations, which describe the magnetic field distribution caused by the ferromagnetic shell presence in the Earth’s magnetic field, are applied. Furthermore, the ability of selecting coils, which fully eliminate the perturbations of the magnetic field outside the shell are proven.
There are electrochemical processes occurring on a metal object surface in seawater. As the result of these processes, one can observe an electric field in the object vicinity. The paper presents the method and measurement system that allows to locate the detected object and to identify parameters of its simplified model in form of a current dipole. The identify method is based on the matrix norm minimization. The matrix contains results of measurements and parameters of the object in request taken as the current dipole. The results of simulation and experimental detection of sea mines are given. The research results confirmed the effectiveness of the developed method.
In marine environment there are different types of objects, such as ships or naval mines, which should be located and identified. One of the location methods is based on the electric potential distribution measurement [1, 2], The object with an insulating or conductive casing, placed in an electric field, causes some field perturbations. For the purpose of the object location the dimensions of the area, where it is possible to determine electric field perturbations by measurement, are important. In this way one can pre-determine the extent of the system for locating and identifying objects placed in the seawater. This paper presents an analytical approach to the perturbation analysis of electric field distribution caused by a sphere and an ellipsoid placed in a uniform electric field. The distance, beyond which the uniform electric perturbations can be neglected, is determined.
Ships made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine parameters of the ship magnetic signature.
A steel-hulled ship in sea water produces an electric field around itself. The source of this field are electrochemical processes and ship’s cathodic protection. The analysis of the electric field around the ship is important by the reason of the ship’s identification and counter-mine protection. The paper presents a simplified model of the ship’s multisource electric field, which allows to calculate the electric field distribution in the so-called distant zone around the ship in an approximate way using a PC, during time lasting from few up to several dozen of minutes.
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Przedstawiono system pomiarowy do badania pola magnetycznego modelu okrętu. System ten będzie wykorzystany przy opracowaniu algorytmów demagnetyzacji okrętów wojennych. Omówiono sposób kompensacji zakłóceń magnetycznych występujących w środowisku.
EN
A measurement system for investigations of the magnetic field of a ship model is presented in the study. The system will be applied in order to work out algorithms for degaussing process of warships. A method of magnetic disturbances compensation occurring in the environment is discussed.
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Results of the analytical and numerical analysis of the degaussing process phenomena of ferromagnetic objects were presented in this paper. The screening effectiveness of the electromagnetic field of magnetic screens in most cases depends on thickness, conductivity [sigma], magnetic permeability [my] of the screen and angular frequency [omega] of degaussing currents. The magnetic field inside thin-layer ferromagnetic object was presented in this paper. Numerical calculations for the quasi-steady state for chosen frequency band were carried out in the Opera 3D.
PL
W pracy przedstawiono analityczną i numeryczną analizę zjawisk występujących podczas procesu demagnetyzacji obiektów ferromagnetycznych. Efektywność ekranowania pola elektromagnetycznego ekranów magnetycznych zależy od grubości ekranu, przewodności elektrycznej, względnej przenikalności magnetycznej oraz częstotliwości prądu demagnetyzacyjnego. Obliczenia numeryczne przeprowadzono w pakiecie Opera 3D.
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W pracy przedstawiono wyniki analizy rozkładu pola magnetycznego wewnątrz rury ferromagnetycznej o skończonej długości. Rura otoczona jest uzwojeniem, w którym płynie prąd sinusoidalnie zmienny. Obliczenia przeprowadzono dla różnych grubości ścianek rury, względnej przenikalności magnetycznej materiału rury oraz różnych wartości konduktywności. Obliczenia rozkładów pola magnetycznego wykonano w programie Opera 3D.
EN
The results of the numerical analysis of the distribution of the magnetic field inside the finite thin-walled ferromagnetic pipe were presented in this paper. The analysis for different values of the thickness walls, relative magnetic permeability and electric conductivity of the pipe was carried out. The analysis of the magnetic field was performed in Opera 3D.
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In this paper, we investigate the application of the asynchronous logic approach for the realization of ultra high-speed digital electronics having higher complexity. We evaluate the possible physical, technological, and schematical origins of restrictions limiting such an application, and propose solutions for their overcoming. Although our considerations are based on the Rapid Single-Flux Quantum technique, the conclusions derived can be generalised about any type of digital information coding.
PL
Pole magnetyczne wewnątrz okrętu podczas procesu demagnetyzacji może być niebezpieczne dla urządzeń elektronicznych. Demagnetyzacja okrętu jest przeprowadzana w celu minimalizacji namagnesowania stałego. W pracy przedstawiono wyniki analizy pola magnetycznego wewnątrz okrętu podczas procesu demagnetyzacji. Analizę numeryczną przeprowadzono w pakiecie OPERA 3D.
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The magnetic field inside the vessel during the degaussing process may be harmful to electronic devices. The degaussing process is crucial for the minimization of the permanent magnetization of the vessel. The results of the analysis of the magnetic field inside the vessel during the degaussing process are presented in this paper. The analysis of the magnetic field was performed in OPERA 3D.
PL
Pole magnetyczne wewnątrz okrętu podczas procesu demagnetyzacji może być niebezpieczne dla urządzeń elektronicznych. Demagnetyzacja okrętu jest przeprowadzana w celu minimalizacji namagnesowania stałego. W pracy przedstawiono wyniki analizy pola magnetycznego wewnątrz okrętu podczas procesu demagnetyzacji. Analizę numeryczną przeprowadzono w pakiecie OPERA 3D.
Metody numeryczne stanowią ważne narzędzie w pracy inżyniera. Dla w pełni świadomego wykorzystania możliwości obliczeniowych oferowanych przez te metody ważne jest ich poznanie i dlatego rośnie coraz bardziej znaczenie nauczania metod numerycznych. Nauczanie jednak nie może się odbywać bez pokazania implantacji metod numerycznych w komputerze i do tego celu bardzo przydatne są programy matematyczne oferowane na rynku. Program, który wspomaga nauczanie powinien umożliwiać przeprowadzenie badań wybranych metod numerycznych, wizualizację wyników oraz zawierać opis algorytmu. Możliwości takie stwarza pakiet MathCad. W pracy przedstawiono przykłady zastosowania pakietu MathCad w nauczaniu metod numerycznych.
EN
Numeric Methods are an important tool in engineer's work. However, for the conscious use of the computations possibilities offered by these methods, the importance of teaching them increases. It is crucial for the study of numeric methods to show their implementations on the computer. Many computer programmes, which are available on the market, are very useful in the study of numeric methods. The computer programme, which helps the study, should allow to test chosen methods, to visualise calculation results and to include the description of algorithms. These possibilities are given by the MathCad System. There are several examples of applying MathCad System in the study of numeric methods presented in this paper.
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