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1
Content available Electrowetting-based beam scanner with controllable field of view
Zhao Rui, Zhang Kai, Kou Songfeng, Wei Xian, Liang Zhongcheng
Optica Applicata
|
2023
|
Vol. 53, nr 4
655--665
EN
A beam scanner based on electrowetting with controllable field of view is designed. Depending on the first-order paraxial approximation, the scanning path and scanning radius of the beam scanner are derived. Its physical model and properties are established and analyzed with the help of by using the COMSOL and MATLAB. The results show that the scanning beam emitting from the beam scanner realizes 360° scanning freely, and its controllable field of view varies from 0 to 65.3 m successfully under the action of working voltage. The two liquid interfaces in the beam scanner can rotate clockwise or counterclockwise independently, and their inclination angle ranges from 0° to 45°. When the two liquid interfaces turn in the same direction, the scanning effect of edge field is better than that of the central zone. While the scanning effect of the central area is greatly improved and better than that of the edge field when the two liquid interfaces turn in the different direction. In addition, the rotation frequencies of the two interfaces affect the performance of the beam scanner.
2
Content available Date Palm Fibre Waste Exploitation for the Adsorption of Congo Red Dye via Batch and Continuous Modes
Ali Qahtan Adnan, Shaban Mohammed Ali A., Mohammed Sabah J., M-Ridha Mohanad J., Abd-Almohi Hussein H., Abed Khalid M., Salleh Muhammad Zulhaziman Mat, Hasan Hassimi Abu
Journal of Ecological Engineering
|
2023
|
Vol. 24, nr 10
259--276
EN
The present study utilised date palm fibre (DPF) waste residues to adsorb Congo red (CR) dye from aqueous solutions. The features of the adsorbent, such as its surface shape, pore size, and chemical properties, were assessed with X-ray diffraction (XRD), BET, Fourier-transform infrared (FTIR), X-ray fluorescence (XRF), and field emission scanning electron microscope (FESEM). The current study employed the batch system to investigate the ideal pH to adsorb the CR dye and found that acidic pH decolourised the dye best. Extending the dye-DPF waste mixing period at 25 °C reportedly removed more dye. Consequently, the influence of the starting dye and DPF waste quantity on dye removal was explored in this study. At 5 g/L dye concentration, 48% dye removal was achieved, whereas at low dye concentrations, only 40% of the dye was removed. The current study also evaluated the DPF particle size created for dye adsorption, yielding a 66% optimal powder size removal. The heat impact assessment performed in this study indicated that increased temperature affected the amount of dye eliminated from aqueous solutions, where a 72% removal was recorded at 45 °C. The pseudo-first- and pseudo-second-order models were utilised to predict the maximum CR dye adsorption with DPF waste. Resultantly, the Langmuir-Freundlich experimental DPF waste CR adsorption documented pseudo-second-order kinetics. In a fixed bed reactor, the DPF waste has been reported to remove CR dye constantly. Consequently, several factors affecting the removal process, including the effects of primary dye, the flow rate of the liquid inside the column, the depth of the filling inside the column, and flow rate were assessed. The results were simulated in the COMSOL® program and compared to practical experiments, which yielded a 99% match. Conclusively, DPF waste could remove several colours from wastewater via active removal.
3
Content available Funnel and Gate Permeable Reactive Barrier Permeable Reactive Barrier Configuration for Contaminated Groundwater Remediation – Designing, Installation, and Modeling: A Review
Mokif Layla Abdulkareem, Faisal Ayad A. H.
Ecological Engineering & Environmental Technology
|
2023
|
Vol. 24, iss. 9
15--33
EN
Groundwater is a valuable resource whose purity is necessary for human survival. It serves as a significant source of water for household, industrial, and agricultural purposes. Traditional groundwater pollution remediation technologies include pump & treat, phase extraction, aeration gas of groundwater, bioremediation, and chemical oxidation. Permeable reactive barrier (PRB) is one of the most key technology being developed as alternatives to the pump and manage method for the remedying contaminated groundwater. An overview on the groundwater significant as important sources for water, sources of groundwater contamination, transport of contaminants, and groundwater remediation technologies have been discussed in this paper. In addition to reactive media, the design and installation of PRBs of funnel-gate configurations and their application as a remediation technique have been covered in this review. Finally reaction mechanisms in groundwater, contaminant transport governing equation, isotherms sorption models, kinetic sorption models, breakthrough curves modeling have been presented in this review. PRB technique provides financial benefits while also encouraging waste material reuse, so contributing to environmental sustainability. Funnel and gate PRB can offer one or more dense treatment areas for maximizing groundwater pollution plume capture. Funnel-gate PRB is characterized by smaller reaction area, ease in replacement and removal during the blocking of the reactive barrier by fine soil particles and reactive sediments.
4
Content available remote Finite element modeling of continuous drive friction welding of Al6061 alloy
Tashkandi Mohammed A.
Materials Science Poland
|
2021
|
Vol. 39, No. 1
1-14
EN
Continuous drive friction welding process is widely used in various industrial applications to assemble shafts, tubes, and many other components. This paper's motivation was developing a CDFW model using the Finite Element Method (FEM). The coupling of the process's thermal and mechanical behaviors was considered during the simulation by COMSOL Multiphysics®. The construction of phase transition curves for Al6061 allowed determining several temperature-dependent thermophysical properties of the material. These properties are then injected in a second simulation to study the temperature evolution during welding. Subsequently, these results are compared and analyzed with the experimental outcomes. Excellent comparability between the model and experimental results was achieved. A unique phenomenon in the welding temperature profile was observed and explained through the model and experimental results interpretation.
5
Content available Ulepszona metoda momentów vs. funkcje pakietu obliczeniowego MATLAB System Identification Toolbox w zakresie estymacji parametrów prostych modeli dynamicznych w niestacjonarnych zagadnieniach wiroprądowych
Dudziak Konrad, Stawicki Krzysztof, Brykalski Andrzej
Poznan University of Technology Academic Journals. Electrical Engineering
|
2019
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No. 97
17--28
PL
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.
EN
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®.
6
Content available Numerical Analysis of a DMA Epoxy-Carbon Composite Study
Kowaleczko P., Panas A., Nowakowski M.
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
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2018
|
Vol. 9, Nr 4 (34)
101--112
EN
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.
PL
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’.
7
Content available Mixed Pseudo-orthogonal Frequency Coding for SAW RFID Tags
Xu M., Xiao X., Yuan Q., Zong Y.
Archives of Acoustics
|
2018
|
Vol. 43, No. 4
681--687
EN
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.
8
Content available remote CFD simulation of heat transfer and fluid flow within metallic foam in forced convection environment
Boulahrouz S., Avenas Y., Chehhat A.
Mechanics and Mechanical Engineering
|
2017
|
Vol. 21, nr 3
611--635
EN
In the present study, a CFD simulation of forced convection in a rectangular block of aluminum foam is investigated. A two energy equations model with the Brinkman-Forchheimer extended Darcy model is considered in the CFD investigation. The governing equations are solved using COMSOL, a commercial multiphysics finite-element PDE solver. Three types of aluminum foam 10-, 20-, 40- pore per inch with different porosity are studied. A parametric study for the range of Reynolds number Re = 250-2000 and the imposed heat flux qw = 0:8−1:6 (W/cm2) is carried out to examine the thermal and the fluid flow behaviors of the aluminum foams. It is found that the plug flow conditions are prevalence for the aluminum foams. The 40-pore per inch aluminum foam has a better heat transfer performance with a larger pressure drop, followed by the 20-, and then by the 10- pore per inch. The validation of the simulation results is made against experimental data from the literature and showed a perfect agreement.
9
Content available Comparison of time-stepping methods for transient magnetic field computations in COMSOL Multiphysics
Sowa M., Typańska D.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2014
|
No. 77
141--147
EN
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.
10
Implementacja modeli nadprzewodników w środowisku COMSOL
Lebioda M., Rymaszewski J.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2012
|
No. 71
33--40
PL
W artykule przedstawiono metody modelowania i symulacji procesów elektromagnetycznych oraz cieplnych w nadprzewodnikach Ii-go rodzaju. Prezentowane modele zaimplementowano w pakiecie COMSOL, umożliwiającym modelowanie procesów fizycznych i przystosowanym do rozwiązywania zagadnień silnie nieliniowych, co jest szczególnie przydatne przy modelowaniu układów nadprzewodnikowych. Utrata właściwości nadprzewodzących przejawia się w postaci szybkiej, nieliniowej zmiany właściwości elektrycznych i magnetycznych materiału, co zdecydowanie utrudnia modelowanie procesów występujących w tej grupie materiałów. Dodatkową trudność stanowi złożony proces chłodzenia i nieliniowy transport ciepła do czynnika chłodzącego, którym najczęściej jest ciecz wrząca. W artykule przedstawiono modele zbudowane w oparciu o predefiniowane interfejsy w zakresie pola elektrycznego i cieplnego oraz modele niezależne, opisane i implementowane bezpośrednio przy pomocy równań różniczkowych cząstkowych (PDE).
EN
The article presents methods for modeling and simulation of electromagnetic and thermal processes in II-type superconductors. The presented models were implemented in the COMSOL package - a versatile set of tools for modeling physical processes, designed to solve highly nonlinear problems. This is particularly desirable feature for modeling superconducting circuits. The loss of superconducting properties is manifested in the form of rapid, nonlinear changes in electrical and magnetic properties of the material, which definitely makes it difficult modeling of processes occurring in this group of materials. An additional difficulty is the complex process of cooling - nonlinear heat transfer to the coolant, which usually is a boiling liquid. This article presents models built with predefined interfaces for applications and independent models, described and implemented directly using partial differential equations (PDEs).
11
Content available remote Technologia wytwarzania układu mikroprzepływowego do amperometrycznego pomiaru stężenia kwasu askorbinowego
Baraniecka A., Górska M., Kazimierczak B., Szmigiel D., Szczypiński R., Ilnicki F., Kruk J., Torbicz W., Pijanowska D., Grabiec P.
Przegląd Elektrotechniczny
|
2010
|
R. 86, nr 10
5-8
PL
W niniejszym artykule zaprezentowano układ mikroprzepływowy do amperometrycznego oznaczania stężenia kwasu L-askorbinowego. Podczas projektowania układu wykorzystano symulacje komputerowe, wykonane za pomocą oprogramowania COMSOL. Do wytworzenia układu zastosowano różne technologie m.in.: głębokie plazmowe trawienie krzemu w procesie Boscha, polimeryzację plazmową, miękką litografię z zastosowaniem krzemowej matrycy i elastomeru PDMS, fotolitografię UV, magnetronowe katodowe napylanie cienkich warstw metalicznych, technikę lift-off, oraz modyfikację elektrochemiczną powierzchni elektrod. W projektowanym układzie do testu immunoenzymatycznego ELISA z wykorzystaniem fosfatazy alkalicznej jako markera, kwas askorbinowy będzie końcowym produktem reakcji enzymatycznej, którego oznaczanie służy do określania w sposób pośredni stężenia istotnych w diagnostyce medycznej agalitów takich jak białko C-reaktywne, fibrynogen i troponiny.
EN
In this paper, a microfluidic system for L-ascorbic acid concentration measurement using the amperometric detection method is presented. The system was developed basing on computer simulations obtained with software COMSOL. Different technologies and techniques such as: deep silicon plasma etching in Bosch method, plasma polymerization, soft lithography with Si template and elastomer PDMS, UV lithography, magnetron sputtering, lift-off and electrochemical surface modification were applied. L-ascorbic acid is electrochemically active compound. In the designed system for immunoenzymatic test ELISA with alkaline phosphatase as an enzymatic label, this compound is a final product of enzymatic reaction. It allows indirect electrochemical measurement of concentration of electrochemically inactive analytes, important in medical diagnostics, such as: C-reactive protein, fibrinogen or troponins.
12
Content available remote Moduł szynowy hybrydowej wyrzutni elektromagnetycznej ze wspomaganiem pneumatycznym – obliczenia elektromechaniczne
Domin J., Kroczek R.
Przegląd Elektrotechniczny
|
2010
|
R. 86, nr 12
36-37
EN
In the paper an electromagnetic and structural field model are presented of a rail of a electromagnetic launcher laboratory stand. Finally analysis is focused on evaluation of forces acting on projectile and stationary parts of the laboratory stand and resulting stresses and deflections.
13
The modelling in COMSOL environment an acoustic screen separating commercial objects from an inhabited area
Idziak P., Antczak M.
Poznan University of Technology Academic Journals. Electrical Engineering
|
2010
|
No. 63
111-118
EN
Problems related to the acoustic protection of inhabited areas, bordering on large shopping centres, were presented in this article. A virtual model of an area protected with an acoustic screen was presented. The model "was built" in COMSOL environment. Calculations were done for many variants of geometric configuration of the screen. Data acquired from a measuring-experiment were used for the calculations.
14
Content available remote CFD modelling of a laminar film flow
Ludwig W., Dziak J.
Chemical and Process Engineering
|
2009
|
Vol. 30, z. 3
417-430
EN
Isothermal liquid film flow along a vertical wall in a evaporator was simulated by the methods of computational fluid dynamics by means of two commercial (CFD) program packages: Fluent and Comsol. The simulations were carried out for glycerol and its solutions, methanol and ethylene glycol for different values of liquid flow rates.
PL
Przedstawiono wyniki modelowania metodami CFD laminarnego spływu filmu cieczy w wyparce cienkowarstewkowej typu statycznego. Symulacje przeprowadzono przy użyciu dwóch pakietów oprogramowania: Fluent i Comsol dla różnych gęstości zraszania oraz cieczy o małej i dużej lepkości. Obliczoną grubość i prędkość filmu porównano z wartościami otrzymanymi na podstawie teorii Nusselta.
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