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Tytuł:
Comparison of time-stepping methods for transient magnetic field computations in COMSOL Multiphysics
Autorzy:
Sowa, M.
Typańska, D.
Powiązania:
https://bibliotekanauki.pl/articles/378331.pdf
Data publikacji:
2014
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
time-stepping
COMSOL
transient magnetic field
Opis:
The computations of a transient magnetic field problem are presented. The problem has been constructed and solved in COMSOL Multiphysics which is one of the most popular and versatile commercial programs that allow to deal with solving electromagnetic field problems by means of the finite element method. A simple 2D problem of a coaxial cable has been chosen so that an analytical solution can be used in order to easily compute an error. The main topic of the paper concerns the comparison of the time-stepping methods that are available in COMSOL Multiphysics i.e. the BDF and generalized alpha methods. It is also possible to select various options for these methods, which have an influence on the solution accuracy. These have been also considered in the analysis.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2014, 77; 141-147
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite element modeling for electric field and voltage distribution along the cap and pin insulators under pollution
Autorzy:
Ghermoul, Oussama
Benguesmia, Hani
Benyettou, Loutfi
Powiązania:
https://bibliotekanauki.pl/articles/2203634.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
1512L
electric field
electrical potential
COMSOL Multiphysics
pollution
pole elektryczne
potencjał elektryczny
zanieczyszczenie
oprogramowanie COMSOL Multiphysics
Opis:
The knowledge of the behavior of both the electric potential and electric field is one of the main factors needed when designing an insulator. Using AutoCAD software a 2D cap and pin 1512L insulator model was created in the clean state and under pollution from one to five insulators separately making a chain of insulators for a total of 10 models. Later they are imported to COMSOL Multiphysics 5.6 software, simulations of the 1512L insulator were made to see the effect the pollution has and the differences that occur on the distribution with the addition of more insulators in the chain. The potential distribution starts to develop a pattern after a certain number of insulators in the chain while the pollution induces high value spikes in the field distribution. Finite-element-analysis for numerical simulation of the pollution effect in outdoor insulators: a review and a novel method.
Źródło:
Diagnostyka; 2023, 24, 2; art. no. 2023201
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of photovoltaic panel cooling beneath a single nozzle based on a configurations framework
Autorzy:
Mzad, Hocine
Otmani, Abdessalam
Powiązania:
https://bibliotekanauki.pl/articles/1845494.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photovoltaic panel
nozzle
dispersion
comsol
glazing
heat transfer
Opis:
Solar cell performance decreases with increasing temperature, heat can reduce output efficiency by 10–25%. The operating temperature plays a key role in the photovoltaic conversion process. Increase in electrical efficiency depends on cooling techniques, in particular photovoltaic modules installed in the high temperature regions. A cooling process using a single nozzle of photovoltaic panel operating under different configurations was simulated. The simulation contains two parts: the first is a thermodynamic investigation of fluid impingement upon the sensor front face. The second is a performance comparison between two types of glass cover. The major result that emerges from this simulation is the effect of a single nozzle arrangement to enhance the cooling process, under a low cadence of impinging droplets in the range 0.1–1.7 m/s.
Źródło:
Archives of Thermodynamics; 2021, 42, 1; 115-128
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research and Modeling of Mechanical Crosstalk in Linear Arrays of Ultrasonic Transducers
Autorzy:
Celmer, M.
Opieliński, K.
Powiązania:
https://bibliotekanauki.pl/articles/176916.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mechanical crosstalk
ultrasonic transducer array
FEM modeling
COMSOL Multiphysics
Opis:
Linear arrays of ultrasonic transducers are commonly used as ultrasonic probes in medical diagnostics for imaging the interior of a human body in vivo. The crosstalk phenomenon occurs during the operation of transducers in which electrical voltages and mechanical vibrations are transmitted to adjacent components. As a result of such additional excitation of the transducers in the array, the directivity characteristics of the aperture used changes, and consequently there is interference with proper operation of a given array and the emergence of distortions in the obtained ultrasound image that reduce its quality. This paper studies the manner of propagation of mechanical crosstalk in the designed model of a linear array of ultrasonic transducers on the basis of unwanted signals, which appeared on elementary piezoelectric transducers when power is supplied to the selected transducer in the array. The universal model of linear array of ultrasonic transducers, which has been developed, allowed the simulation of mechanical crosstalk, taking into account the cross-coupling phenomenon in all of its structure with the use of finite elements method (FEM) implemented in COMSOL Multiphysics software. The analysis of crosstalk signals showed that they consist of aggregated pulses propagating with different speeds and frequencies. This signifies the formation of different vibration modes transmitted simultaneously via different paths. The paper is an original approach which enables to identify different vibration modes and estimate their participation in the crosstalk signal and their ways of propagation. Conclusions from the research allow predicting specific design changes which are significant due to the minimization of mechanical crosstalk in linear arrays of ultrasonic transducers.
Źródło:
Archives of Acoustics; 2016, 41, 3; 599-612
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault detection and diagnosis of squirrel cage asynchronous motor using a new COMSOL multiphysics software 6.0.
Autorzy:
Djaidir, Benrabeh
Nail, Bachir
Rouibah, Abdelkader
Powiązania:
https://bibliotekanauki.pl/articles/27313810.pdf
Data publikacji:
2024
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
asynchronous motor
comsol multiphysics
diagnosis
fault detection
flux density
Opis:
In this paper, the diagnosis of faults in squirrel cage asynchronous motor and experimental analysis process are presented. Currently there are several simulation tools, that lets users analyze and interpret the behavior of their devices. Based on this, there is a lot of researches that is working on developing models, to detect and classify 3-phase asynchronous motor faults, significantly in the early stages. This work proposed design and experimental analysis established in Comsol Multiphysics 6.0 , which implements finite element analysis software (FEM) for detecting and diagnosing broken bar rotors of this types motors and its practical application. In this case, the post processor of the COMSOL-Multiphysics makes it possible to visualize in 2D the various magnetic and mechanical quantities. Through the curves of the magnetic flux density and analysis distribution of the field with magnetic induction lines, we can draw some conclusions, where we proposed an strategy, for detecting and diagnosing faults consistent with the structure of the software.
Źródło:
Diagnostyka; 2024, 25, 1; art. no. 2024102
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational Fluid Dynamics Modeling of Residence Time Distribution in a Field-Scale Horizontal Subsurface Flow Constructed Wetland with Palm Kernel Shell as Substrate
Autorzy:
Okoye, Nelson Mbanefo
Madubuike, Chimaobi Nnaemeka
Nwuba, Ifeanyi Uba
Orakwe, Louis Chukwuemeka
Ugwuishiwu, O. Boniface
Powiązania:
https://bibliotekanauki.pl/articles/1163287.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
COMSOL
Computational Fluid Dynamics
Constructed Wetland
Simulation Modelling
Wastewater Treatment
Opis:
The hydraulic performance of constructed wetlands is often compromised by hydraulic problems. Therefore, the development of an appropriate simulation model to reliably predict how various modifications of bed design and configurations might affect performance will facilitate the design of efficient systems. The aim of this research work is to determine distribution of residence time in a field-scale horizontal subsurface flow constructed wetland with Palm Kernel Shell as substrate. The governing equations of flow in porous media and transport of diluted species were solved using COMSOL Multiphysics 5.3a. The result was validated using experimental data and the model result showed good agreement with a correlation coefficient of 0.99. Alternative wetland designs were assessed for the same flow conditions. The results revealed that a two cell wetland improved short-circuiting flow paths.
Źródło:
World Scientific News; 2018, 109; 60-70
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Analysis of a DMA Epoxy-Carbon Composite Study
Analiza numeryczna metodyki badań DMA kompozytu epoksydowo-węglowego
Autorzy:
Kowaleczko, P.
Panas, A.
Nowakowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/403771.pdf
Data publikacji:
2018
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
composite material
DMA
numerical simulation
COMSOL
materiał kompozytowy
symulacja numeryczna
Opis:
The results of numerical simulations performed for Dynamic Mechanical Analysis (DMA) measurements of thermal and mechanical (or thermomechanical) properties performed on a model composite structure are presented herein. The simulated elastic response of an epoxy-carbon fibre composite specimen was analysed for a case by which the model specimen was subjected to three-point bending with a free support. The epoxy-carbon fibre composite studied as explained herein exhibited extreme differences between the elastic properties of the epoxy resin matrix and the carbon fibre reinforcement. In addition, the carbon fibre reinforcement was both internally and structurally anisotropic. The numerical simulations were performed to demonstrate a qualitative dependence of the DMA measurement results on a certain structure of the investigated specimen and to determine if the DMA results could be qualified as effective or apparent. A macro-mechanical model of the specimen was developed and the numerical calculations were performed by applying a COMSOL/M FEM (Finite Element Method) modelling software. The carbon fibre reinforcement was modelled with an orthotropic composite structure of planar laminar inclusions or as a disperse composite with circular inclusions. While modelling different characteristic dimensions of inclusions were taken into account. Representative material properties were assumed from the results of the appropriate experimental investigations and form certain literature reference data. The effect of the composite layer configuration and their characteristic dimensions on the evaluated model elastic modulus value was also studied. The numerical modelling results are in a qualitative agreement with the results of the DMA investigations performed on real composite. They also proved the effectiveness of the developed numerical simulation methodology in modelling of micro- and macromechanical phenomena occurring during the DMA study.
W pracy przedstawiono wyniki numerycznych badań symulacyjnych pomiaru właściwości cieplnomechanicznych (termomechanicznych) struktury kompozytowej. Uwagę skupiono na symulacji sprężystej odpowiedzi próbki kompozytu epoksydowo-węglowego poddanego analizie termomechanicznej DMA (Dynamic Mechanical Analysis) w trybie zginania z trójpunktowym swobodnym podparciem. Kompozyt epoksydowo-węglowy jako obiekt analizy charakteryzuje się bardzo dużą dysproporcją właściwości sprężystych materiału osnowy i wypełnienia. Dodatkowo cechy anizotropii wykazuje już sam materiał wypełnienia w postaci włókien węglowych. Celem wykonanych badań numerycznych było jakościowe określenie wpływu struktury na wyniki badań DMA i określenie możliwości zaklasyfikowania uzyskiwanych wyników jako właściwości efektywnych bądź pozornych. Do opracowania modelu makromechanicznego badanej próbki i przeprowadzenia obliczeń wykorzystano program modelowania MES COMSOL. Wypełnienie włóknami węglowymi modelowano za pomocą ortotropowych wtrąceń warstwowych lub kołowych o różnych wymiarach charakterystycznych. Reprezentatywne dane materiałowe przyjęto na podstawie wyników badań własnych i danych literaturowych. Zbadany został wpływ rozmieszczenia poszczególnych warstw oraz ich wymiaru charakterystycznego na określany z modelowej zależności moduł sprężystości E’.
Źródło:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa; 2018, 9, 4 (34); 101-112
2081-5891
Pojawia się w:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie trójwymiarowego rozkładu pola temperatury w elektromagnetycznym układzie chwytnym z wykorzystaniem środowiska Comsol
3D thermal field modelling in electromagnetic gripping system using Comsol Multiphisics
Autorzy:
Barański, Mariusz
Glapa, Krystian
Powiązania:
https://bibliotekanauki.pl/articles/378149.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
elektromagnetyczny układ chwytny
ujęcie 3D
zjawiska cieplne
oprogramowanie Comsol
Opis:
W artykule przedstawiono opracowany w środowisku Comsol trójwymiarowy polowy model elektromagnetycznego układu chwytnego do analizy rozkładu pola temperaturowego. Wykorzystany w pracy elektromagnetyczny układ chwytny, stanowiący składową kończyny dwunożnego robota kroczącego, został zaprojektowany przez autorów. Przedstawiono algorytm obliczeń analitycznych elektromagnesu oraz proces modelowania rozkładu pola cieplnego w środowisku Comsol. Przeprowadzono obliczenia symulacyjne, w trakcie których analizowano wpływ prądu zasilającego cewkę elektromagnesu oraz szerokości szczeliny powietrznej na rozkład pola temperaturowego w stanie cieplnie ustalonym. Zaprezentowano wybrane rezultaty badań symulacyjnych oraz wynikające z nich wnioski.
In this paper, 3D steady-state thermal field modeling in electromagnetic gripping system using Comsol Multiphisics was presented. The electromagnetic gripping system, which is a component of the mechanical leg of a walking robot was designed by the authors. An algorithm to design of the electromagnetic gripping as well as mathematical model of electromagnetic and thermal phenomena was developed. During calculations, the influence of the value of the current as well as the influence of the air gap width on the thermal field distribution in steady-state was carried out. Selected results of simulations as well as the analysis of these results were presented.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2019, 99; 73-83
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ulepszona metoda momentów vs. funkcje pakietu obliczeniowego MATLAB System Identification Toolbox w zakresie estymacji parametrów prostych modeli dynamicznych w niestacjonarnych zagadnieniach wiroprądowych
Improved method of moments vs. functions of the MATLAB Identification Toolbox calculation package in the scope of estimation of simple parameters of dynamic models in eddy curent problems
Autorzy:
Dudziak, Konrad
Stawicki, Krzysztof
Brykalski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/378387.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
zmodyfikowana metoda momentów
model transmitancyjny
dynamika pola elektromagnetycznego Matlab
COMSOL
Opis:
Jedną z niewielu metod, pozwalających na wykorzystanie do estymacji parametrów modeli transmitancyjnych charakterystyki częstotliwościowej jest metoda momentów. W niniejszej pracy, na przykładach dynamicznych zagadnień wiroprądowych, autorzy przedstawią porównanie uproszczonych typowe modeli transmitancyjnych otrzymanych z charakterystyki częstotliwościowej i czasowej. Zbadana będzie zgodność modeli wyznaczonych ulepszoną metodą momentów z analogicznymi modelami uzyskanymi z wykorzystaniem komercyjnego pakietu obliczeniowego System Identification Toolbox™ (SIT) z pakietu MATLAB®. Adekwatność modeli uzyskanych ulepszoną metodą momentów oraz niezależnie, dzięki pakietowi System Identification Toolbox™, będzie sprawdzona przez porównanie zgodności odpowiednich charakterystyk czasowych i częstotliwościowych, uzyskanych przez rozwiązanie równania przewodnictwa lub zespolonego równania Helmholtza w programie COMSOL Multiphysics®. Autorzy wykażą konkurencyjność, a w niektórych przypadkach przewagę zmodyfikowanej metody momentów nad wybranymi funkcjami komercyjnego narzędzia.
One of the few methods allowing to use the frequency response models for estimation of parameters is the improved moment method. In this paper, on selected examples of dynamic eddy current problems, the authors will practically present how simplified, typical transfer function`s models can be obtained from the frequency response of computer methods. The compatibility of the models determined by an improved method of moments with similar models obtained using the commercial System Identification Toolbox ™ from the MATLAB® package will be tested. The adequacy of the models obtained with the improved torque method and independently, thanks to the System Identification Toolbox ™, will be checked by comparing the compatibility of the relevant time characteristics and frequency characteristics obtained before direct solution of the conduct equation or complex Helmholtz equation in the COMSOL Multiphysics® program. The authors will show competitiveness and in some cases the advantage of an improved method of moments over selected features of the commercial System Identification Toolbox ™ for MATLAB®.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2019, 97; 17-28
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of the Moulding Process of Bentonite-Bonded Green Sand
Autorzy:
Abdulamer, D.
Kaduaw, A.
Powiązania:
https://bibliotekanauki.pl/articles/1837740.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
green sand mould
moulding processes
COMSOL multiphysics
time-dependent study
Opis:
Finite Element Method FEM via commercially available software has been used for numerical simulation of the compaction process of bentonite-bonded sand mould. The mathematical model of soil plasticity which involved Drucker-Prager model match with Mohr Coulomb model was selected. The individual parameters which required for the simulation process were determined through direct shear test based on the variation of sand compactability. The novelty of this research work is that the individual micro-mechanical parameters were adopted depend on its directly proportional to the change of sand density during the compaction process. Boundary conditions of the applied load, roller and fixed constraint were specified. An extremely coarse mesh was used and the solution by time-dependent study was done for investigation of material-dependent behaviour of green sand during the compaction process. The research implemented also simulation of the desired points in sand mould to predict behaviour of moulding process, and prevent failure of the sand mould. Distance dependent displacement and distance-dependent pressure have been determined to investigate the effective moulding parameters without spent further energy and cost for obtaining green sand mould. The obtained numerical results of the sand displacement show good agreement with the practical results.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 67-73
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of the Moulding Process of Bentonite-Bonded Green Sand
Autorzy:
Abdulamer, D.
Kaduaw, A.
Powiązania:
https://bibliotekanauki.pl/articles/1837861.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
green sand mould
moulding processes
COMSOL multiphysics
time-dependent study
Opis:
Finite Element Method FEM via commercially available software has been used for numerical simulation of the compaction process of bentonite-bonded sand mould. The mathematical model of soil plasticity which involved Drucker-Prager model match with Mohr Coulomb model was selected. The individual parameters which required for the simulation process were determined through direct shear test based on the variation of sand compactability. The novelty of this research work is that the individual micro-mechanical parameters were adopted depend on its directly proportional to the change of sand density during the compaction process. Boundary conditions of the applied load, roller and fixed constraint were specified. An extremely coarse mesh was used and the solution by time-dependent study was done for investigation of material-dependent behaviour of green sand during the compaction process. The research implemented also simulation of the desired points in sand mould to predict behaviour of moulding process, and prevent failure of the sand mould. Distance dependent displacement and distance-dependent pressure have been determined to investigate the effective moulding parameters without spent further energy and cost for obtaining green sand mould. The obtained numerical results of the sand displacement show good agreement with the practical results.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 67-73
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Simulation Research of Two-Dimensional Distribution in Gas-Solid Two-Phase Flow by Backscattering Method
Autorzy:
Fan, Jinhui
Wang, Fei
Powiązania:
https://bibliotekanauki.pl/articles/31339986.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
gas-solid two-phase flow
COMSOL simulation
ultrasonic backscattering method
Opis:
The two-dimensional distribution of gas-solid flow parameters is a great research significance to reflect the actual situation in industry. The commonly used method is the ultrasonic tomography method, in which multiple probes are arranged at various angles, or the measurement device is rotated as that in medicine, but in most industrial situations, it is impossible to install probes at all angles or rotate the measured pipe. The backscattering method, however, uses only one transducer to both transmit and receive signals, and the two-dimensional information is obtained by only rotating the transducer. Ultrasound attenuates greatly in the air, and the attenuation changes with frequency. Therefore, Comsol is used to study the reflection of particles with different radii in the air to ultrasound with various frequencies. It is found that the backscattering equivalent voltage is the largest when the product of ultrasonic frequency and particle radius is about 27.78 Hz·m, and the particle concentration of 30% causes the strongest backscattering. The simulated results are in good agreement with the Faran backscattering model, which can provide references for selecting the appropriate frequency and obtaining the concentration when measuring gas-solid two-phase flow with the ultrasonic backscattering method.
Źródło:
Archives of Acoustics; 2022, 47, 3; 373-382
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite element method based simulation of electrical breakage of iron-phosphate ore
Autorzy:
Razavian, S. M.
Rezai, B.
Irannajad, M.
Powiązania:
https://bibliotekanauki.pl/articles/110295.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
finite element method
numerical simulation
electrical breakage
iron-phosphate ore
COMSOL Multiphysics
Opis:
In this study, the effect of minerals composition, particle size and shape as well as electrodes distance from iron-phosphate ore samples, was investigated by using a commercial software. Comparison between high voltage pulses and conventional crushing showed that minerals of interest in the electrical comminution product are better liberated than in the conventional comminution. In order to elucidate and confirm the experimental results, numerical simulation of electrical field distributions/intensity were performed. The software uses the finite element method, a numerical technique for calculating approximate solutions of partial differential equations with known boundary conditions. Magnetite, apatite and quartz were the basic minerals of iron-phosphate ore components, and the main material property used in the simulations was electrical permittivity. The results showed that the induced electrical field was strongly dependent on the electrical properties of minerals, the feed particle size and the location of the magnetite mineral (due to higher permittivity) in the ore. The angle of particle contact surface with high voltage electrode was an important factor in the intensity of electrical field. Smaller contact angle resulted in higher intensity of the electrical field. Electrical discharge within the material was converted to electrohydraulic discharge within the surrounding water environment by increasing the distance between the high voltage electrode and the material contact surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 1; 137-150
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical model of the axial magnetic bearing with six cylindrical poles
Autorzy:
Sikora, Bartłomiej Marian
Pilat, Adam Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/141281.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Active Magnetic Bearing
Axial Magnetic Bearing
Finite Element Method
numerical model
COMSOL Multiphysics
Opis:
The paper presents a numerical model of the novel design of the axial magnetic bearing with six cylindrical poles. The motivation behind this idea was to eliminate vibra- tions in rotating machinery due to the axial load. Common conception of such a bearing provides a single component of the electromagnetic force, which is not enough to reduce transverse and lateral vibrations of the armature. The proposed design allows for avoiding wobbling of the disc with the use of a few axial force components that are able to actively compensate the axial load and stabilise the disc in a balanced position. Before a real device is manufactured, a virtual prototype should be prepared. The accurate numerical model will provide essential knowledge about the performance of the axial magnetic bearing.
Źródło:
Archives of Electrical Engineering; 2019, 68, 1; 195-208
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mixed Pseudo-orthogonal Frequency Coding for SAW RFID Tags
Autorzy:
Xu, M.
Xiao, X.
Yuan, Q.
Zong, Y.
Powiązania:
https://bibliotekanauki.pl/articles/176715.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
SAW RFID tag
OFC
POFC
Mixed-POFC
mixed pseudo-orthogonal frequency coding
COMSOL
Opis:
A mixed pseudo-orthogonal frequency coding (Mixed-POFC) structure is proposed as a new spreadspectrum technique in this paper, which employs frequency and time diversity to enhance tag properties and balances the spectrum utilization and code diversity. The coding method of SAW RFID tags in this paper uses Mixed-POFC with multi-track chip arrangements. The cross-correlation and auto correlation of Mixed-POFC and POFC are calculated to demonstrate the reduced overlap between the adjacent center frequencies with the Mixed-POFC method. The center frequency of the IDT and Bragg reflectors is calculated by a coupling of modes (COM) module. The combination of the calculation results of the Bragg reflectors shows that compared with a 7-chip POFC, the coding number of a 7-chip Mixed-POFC is increased from 120 to 144 with the same fractional bandwidth of 12%. To demonstrate the validity of Mixed-POFC, finite element analysis (FEA) technology is used to analyze the frequency characteristics of Mixed-POFC chips. The maximum error between designed frequencies and simulation frequencies is only 1.7%, which verifies that the Mixed-POFC method is feasible.
Źródło:
Archives of Acoustics; 2018, 43, 4; 681-687
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 19

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