Wyniki wyszukiwania - BazTech

1

Design of localized surface plasmon resonance-based refractive index sensor using optical fiber

Yadav Mukti, Kaler R. S.

Optica Applicata

|

2024

|

Vol. 54, nr 1

85--96

EN

The paper proposes a design of a localized surface plasmon resonance-based refractive index sensor for the detection of a chemical compound availing unclad geometry of the optical fiber. The geometry is explored to analyze the sensing behavior and coupling phenomenon at the metal-dielectric interface. The finite element method (FEM) is applied numerically to evaluate the analytical change in the reflectance spectra of the fiber model by inoculating potassium nitrate compound. The resonance shift and reflectance of the surface plasmon resonance (SPR) signal obtained after the optimization of structural parameters enhance the sensing performance of the prototype. The sensor exhibits a maximum sensitivity of 80.2919 rad/RIU for a 1.56 high refractive index analyte and minimum sensitivity of 2.3446 rad/RIU for a 1.33 low refractive index analyte. The proposed sensor is modelled in such a way that it can be employed in various sensing applications for a wide range of refractive indices.

2

Finite element modeling for electric field and voltage distribution along the cap and pin insulators under pollution

Ghermoul Oussama, Benguesmia Hani, Benyettou Loutfi

Diagnostyka

|

2023

|

Vol. 24, No. 2

art. no. 2023201

EN

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.

3

A proper borehole pattern design for coal seam methane drainage in Tabas coal mine using Comsol Multiphysics

Bagherzadeh Ali, Najafi Mehd, Marji Mohammad Fatehi, Noroozi Mehdi

Journal of Sustainable Mining

|

2022

|

Vol. 21, iss. 1

54--64

EN

Optimizing the operational parameters of the borehole pattern in the coal seam includes the maximum amount of gas to be drained with the least amount of drilling, investment, and drainage time. The main purpose of this research is to properly design the drainage borehole pattern in the C1 coal seam of the Tabas coal mine. In this research, the Comsol Multiphysics software was used for numerical modeling of the boreholes. According to the method of diffusion of methane gas in a coal seam, the reduction of methane gas concentration and the amount of gas released from the coal blocks were approximated. For the gas drainage boreholes, the three patterns of the rectangular, parallelogram, and triangular forms were considered. Also, the boreholes were modeled with the three diameters of 76, 86, and 96 mm. This modeling was performed for 180 days of drainage operation and showed that the triangular pattern was more suitable than the other two patterns. The presented model is applicable in coal mines where gas drainage operations are necessary and helps engineers design the patterns of drainage boreholes to maximize their gas drainage efficiency.

4

Simulation of eddy current and repulsive force of non-ferrous particles in eddy current separator

Ayad Ahmed Nour El Islam, Larab Moulay, Boudjella Houari, Benhamida Farid

Przegląd Elektrotechniczny

|

2019

|

R. 95, nr 6

47--50

EN

Eddy-current separation can be an effective technique for sorting non-ferrous metals from nonmetallic wastes. In this paper, we simulate the magnetic characteristics of rotational eddy current separator rounded by drum of permanents magnets in two dimensions, used to sort a mixture of non ferrous particles of different nature. The induced current and magnetic force of ejection in different kind and size of non-ferrous particles are simulated and computed by using the finite element method with Comsol Multiphysics software. The aim of this work is to show the magnetic performance of separator and induced current density in particles, the influence of the conductivity of each of non-ferrous particles on the eddy current and the repulsion force.

PL

W artykule przedstawiono symulację pracy separatora magnetycznego z bębnem złożonym z magnesów i wykorzystującego prądy wirowe. Układ separatora i charakterystyki separowanych elementów modelowane są metodą elementu skończonego z wykorzystaniem oprogramowania Comsol Multiphysics.

5

Analysis of Epstein frame by finite element method

Németh Zoltan, Kuczmann Miklós

Przegląd Elektrotechniczny

|

2019

|

R. 95, nr 6

23--26

EN

An Epstein frame has been built, which is used to measure magnetic properties of different kind of cores. Sinusoidal voltage excitation has been used in a frequency range of 1-400Hz. The measurements have been performed by a computer-controlled measurement system. The building and the measurement process have been published before. The objective of this work is to compare the simulation results performed with the COMSOL Multiphysics build-in modules and some potential formulation. For this work the Jiles-Atherton model has been chosen to prescribe hysteresis phenomena. The model parameters can be obtained by using the measurement results. The frame has been modelled in 2D.

PL

W artykule zaprezentowano analizę systemu wykorzystującego platformę COMSOL Multiphysics. Użyto modelu Jiles-Atherton do opisu histerezy. Przeprowadzono analizę 2D wykorzystując parametry uzyskane doświadczalnie.

6

Numerical model of the axial magnetic bearing with six cylindrical poles

Sikora Bartłomiej Marian, Pilat Adam Krzysztof

Archives of Electrical Engineering

|

2019

|

Vol. 68, nr 1

195--208

EN

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.

7

Układ pomiarowy do badań charakterystyk chłodzenia radiatorów z wykorzystaniem pomiarów termowizyjnych

Klecha D., Minkina W.

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

|

2017

|

Nr 54

117--121

PL

W artykule przedstawiono metodę pozwalającą na porównanie jakości chłodzenia wybranych typów radiatorów w warunkach konwekcji swobodnej z wykorzystaniem pomiarów termowizyjnych oraz autorskiego stanowiska badawczego. W tym celu zbudowano układ pomiarowy, który może być użyty do generowania identycznych temperatur pod czterema polami grzewczymi w tym samym czasie i w tych samych warunkach wymiany ciepła. Na obszarze pól grzewczych umieszczono badane radiatory. Odczyty wartości temperatury z analogowych czujników temperatury i termogramów zostały użyte do porównania, który radiator ma najniższa temperaturę na początku i na końcu pomiarów. Wyniki badań eksperymentalnych porównano z wynikami badań modelowych z wykorzystaniem środowiska programistycznego COMSOL Multiphysics®. Pozycje literaturowe w małym stopniu opisują podobną problematykę. Na podstawie wyników uzyskanych z przeprowadzonych pomiarów i badań modelowych, sformułowano wnioski dotyczące jakości chłodzenia wybranych typów radiatorów.

EN

The aim of t his paper is to discuss method to compare cooling parameter in selected radiators. In this purpose measurement system was created which can be used to generate identical temperature under four radiators in the same time and conditions. Readings from analog sensors and thermograms were used to compare which radiator has the lowest temperature at the beginning and at the end of the measurement. Paper describes method to compare radiators using measurements from sensors and thermograms which is supplement to the theoretical calculations. Literature positions discuss this method slightly. Method is given capabilities to analyse whole process of cooling and deduce additional conclusions. Differences between temperatures of the radiators are noticeable and can be used to select the most performance radiator. The model research was compared with calculations form COMSOL Multiphysics®. The coolest radiator was different than this from experiment. This is the initial research. Next stage of the work will be carried out extensive research with the other radiators which will contain different shapes, weights and surface areas.

8

Obliczenia numeryczne rozkładu temperatury w transformatorze dystrybucyjnym

Gościński P., Dombek G., Nadolny Z., Bródka B.

Przegląd Elektrotechniczny

|

2016

|

R. 92, nr 10

46--49

PL

W artykule przedstawiono porównanie wyników symulacji komputerowej i wyników pomiarów z próby nagrzewania transformatora dystrybucyjnego o mocy 10 MVA wypełnionego nowym olejem mineralnym. Następnie autorzy artykułu postanowili przeprowadzić symulację komputerową w celu porównania pola temperaturowego transformatora energetycznego wypełnionego nowym olejem mineralnym z polem temperaturowym transformatora tej samej mocy wypełnionego estrem syntetycznym.

EN

This article presents comparison between results of computer simulation and results of heat run test for 10 MVA power transformer which was filled with a new mineral oil. Later the authors of article decided to carry out computer simulation, in order to comparison the temperature field of 10 MVA power transformers which were filled a new mineral oil and a new synthetic ester.

9

Research and Modeling of Mechanical Crosstalk in Linear Arrays of Ultrasonic Transducers

Celmer M., Opieliński K.

Archives of Acoustics

|

2016

|

Vol. 41, No. 3

599--612

EN

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.

10

Finite element method based simulation of electrical breakage of iron-phosphate ore

Razavian S. M., Rezai B., Irannajad M.

Physicochemical Problems of Mineral Processing

|

2015

|

Vol. 51, iss. 1

137--150

EN

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.

11

Modelowanie MES procesu azotowania części maszyn

Ratajski J., Olik R., Szparaga Ł.

Inżynieria Powierzchni

|

2013

|

nr 2

3--11

PL

W artykule zamieszczono przykłady zastosowania MES do obliczeń czasoprzestrzennego rozkładu stężenia azotu w azotowanych modelowych elementach o kształcie kubicznym oraz w modelowym kole zębatym. W tym celu zaimplementowano model kinetyki wzrostu warstwy azotowanej Fe(N) w środowisku Comsol Multiphysic, dla tych dwóch rozważanych obiektów modelowych. Do dyskretyzacji obiektu zastosowano element skończony typu Lagrange-Quadratic o kształcie tetragonalnym. Wyniki obliczeń zobrazowano w postaci: mapy rozkładów stężeń, izopowierzchni stężenia, klasycznych profili rozkładów stężenia azotu w funkcji odległości od powierzchni oraz zmiany stężenia azotu w formie wykresu trójwymiarowego we współrzędnych: stężenie, czas oraz odległości od powierzchni.

EN

FEM application examples are given for calculations of concentration distributions of nitrogen in function of time and spatial coordinates in the nitrided model cubic-shaped elements and gear-wheel model. For this purpose, the model of nitrided layer growth kinetics Fe(N) was implemented in Comsol Multiphysic environment for these two model objects considered. For discretization were used a finite element of Lagrange-Quadratic type of tetragonal shape. The results of the calculations illustrated in the form of map distributions of nitrogen concentration, concentrationisosurfaces, classic profiles of nitrogen concentration distributions as function of a distance from the surface and of the changes nitrogen concentration in form of a three-dimensional graph coordinates: concentration, time and distance from the surface.

12

Modelowanie złożonej wymiany ciepła w procesie wytwarzania spieku 90W-7Ni-3Fe

Sypek J., Majewski T., Panas A.

Biuletyn Wojskowej Akademii Technicznej

|

2011

|

Vol. 60, nr 2

297-312

PL

Przedstawiono wyniki analizy numerycznej procesu wytwarzania metalu ciężkiego (spieku ciężkiego) 90W-7Ni-3Fe. Modelowano rzeczywisty układ stosowany do wytwarzania takiego materiału metodą nagrzewania rezystancyjnego. Do budowy modelu i wykonania obliczeń zastosowano pakiet Comsol Multiphysics. Analizę przeprowadzono przy założeniach upraszczających wynikających z ograniczonych możliwości środowiska obliczeniowego i braku pełnych charakterystyk materiałowych w całym analizowanym zakresie temperatury. W modelu odtworzono jednak wszystkie główne zjawiska i uzyskano możliwość jakościowej analizy przebiegu procesu spiekania, identyfikacji problemów technologicznych oraz optymalizacji procesu spiekania rezystancyjnego.

EN

Results of numerical analysis of 90W-7Ni-3Fe heavy alloy (WHA) production process were presented in the paper. Real system used for production of such material by resistance heating method was modelled applying Comsol Multiphysics FEM software. The analysis was focussed on complex, i.e., combined heat transfer phenomena including phase change effects. Despite some necessary simplifications, all the main phenomena were reconstructed in the numerical model. The numerical modelling enabled for qualitative and quantitative, in some aspect, analyses of the sintering processes and for identification of main technological problems. It also made possible optimisation of the analysed powder metallurgy production process.