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- 摘要
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- 实验方案
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[IEEE 2019 2nd International Conference on High Voltage Engineering and Power Systems (ICHVEPS) - Denpasar, Bali, Indonesia (2019.10.1-2019.10.4)] 2019 2nd International Conference on High Voltage Engineering and Power Systems (ICHVEPS) - A Review of Feed-In Tariff Model (FIT) for Photovoltaic (PV)
摘要： In this paper, a solution to the double curl equation with generalized Coulomb gauge is proposed based on the vectorial representation of the magnetic vector potential. Traditional Coulomb gauge is applied to remove the null space of the curl operator and hence the uniqueness of the solution is guaranteed. However, as the divergence operator cannot act on edge elements (curl-conforming) directly, the magnetic vector potential is represented by nodal elements, which is too restrictive, since both the tangential continuity and the normal continuity are required. Inspired by the mapping of Whitney forms by mathematical operators and Hodge (star) operators, the divergence of the magnetic vector potential, as a whole, can be approximated by Whitney elements. Hence, the magnetic vector potential can be expanded by the edge elements, where its vectorial nature is retained and only the tangential continuity is required. Finally, the original equation can be rewritten in a generalized form and solved in a more natural and accurate way using finite-element method.
关键词： Whitney forms,generalized Coulomb gauge,Finite-element method (FEM),magnetostatic
更新于2025-09-16 10:30:52
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Developer Design of Hybrid Plasmonic Nano Patch Antenna with Metal Insulator Metal Multilayer Construction
摘要： Hybrid plasmonic nanopatch antenna with metal-insulator-metal (HMIM) multilayer has been investigated for operation at the frequency of 125–250 THz using the finite element method (FEM) implemented in Ansoft High Frequency Structure Simulator (HFSS). The proposed antenna exhibits a wide bandwidth of 49.5 THz (151.5 THz–201 THz) for the slots thicknesses Wg = 50 nm and Ws = 100 nm and dual bandwidth for Ws = 20 nm. The obtained results show the input impedance of 50.3 Ω input resistance (real part) and 2.3 Ω reactance (imaginary part) occurring at (near) the operation frequency. The maximum gain of 23.98 dB has been observed for resonant frequencies of 176 THz, and the maximum directivity remains above 6.73 dB and 7.46 dB at resonant frequencies of 170 THz and 190 THz, respectively. Our proposed antenna performance is compared to previously reported designs. The copolar and cross-polar radiation patterns are simulated at different resonant frequencies of 160 THz and 197 THz for planes Φ = 90° and Φ = 0° . The arrays of a proposed antenna are designed in one and two dimensions in order to appropriate high-gain applications.
关键词： Ansoft High Frequency Structure Simulator,wide bandwidth,hybrid plasmonic nanopatch antenna,high-gain applications,metal-insulator-metal,finite element method
更新于2025-09-12 10:27:22
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Design of a Plasmonic Platform to Improve the SERS Sensitivity for Molecular Detection
摘要： We suggested a plasmonic platform based on a cubic pattern of gold spheres for surface enhanced Raman spectroscopy (SERS). In the case of linear polarization along the symmetry axes, the SERS enhancement per area is identical to hexagonally patterned surfaces. The validity of this model was tested using the simulation package of COMSOL Multiphysics? Modeling Software. We found an improved sensitivity in the near infrared and visible region of the electromagnetic spectrum. This method considered tolerance towards stacking faults and suggested a plasmonic platform for ultra-sensing applications. The design can be extended towards the molecular detection if the proposed plasmonic platform is used with SERS.
关键词： sensitivity,SERS enhancement,Plasmonic platform,finite element method
更新于2025-09-12 10:27:22
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Mid-infrared sensing properties of a plasmonic metal-insulator-metal waveguide with a single stub including the defects
摘要： A highly sensitive surface plasmon polariton (SPP) based sensor with a simple structure that composes of a metal-insulator-metal waveguide with a single stub including several silver nanorod defects, is designed and numerically investigated using finite element method for the applications of refractive index sensors and temperature sensors. The simulation results show that the existence of silver nanorod defects in the single stub have a great influence on the sensitivity performance, which provides an additional degree to manipulate the system response in the nanometer scale. The refractive index sensitivity can be reached as high as 5140 nm/RIU (RIU is refractive index unit) and the temperature sensitivity is about 2.05 nm/0C, which can be further improved by varying the length of stub (h), radius of defect rod (r) and the number of defects (N) in the stub. The sensing characteristics of the proposed simple structure would pay the way for highly integrated optical circuits for designing nanoscale refractive index sensors and temperature sensors with the single stub including the defects.
关键词： integrated optical circuits,refractive index sensors,silver nanorod defects,metal-insulator-metal waveguide,temperature sensors,surface plasmon polariton,finite element method
更新于2025-09-12 10:27:22
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Optimizing on thermoelectric elements footprint of the photovoltaic-thermoelectric for maximum power generation
摘要： A finite element method (FEM) model for the hybrid PV-TE uni-couple is presented to determine the optimal geometry of the thermoelectric generator (TEG) element for the maximum efficiency. The three-dimensional (3D) governing equations of the thermoelectric for the heat transfer are solved using the FEM based on the temperature dependent properties of TEG materials. The geometric parameters of the TEG were anlyzed in the simulation include the ratio of the area of n- and p-type (An/Ap), the length and the area of the TEG. The result shows that for different areas and different lengths of TEG, the maximum power outputs of the PV-TE all occur with An/Ap = 1 which is different from the TEG solely optimization. This study will provide the valuable reference for PV-TE design.
关键词： finite element method,maximum efficiency,PV-TE,temperature distribution,footprint
更新于2025-09-12 10:27:22
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Analysis of distortion during laser metal deposition of large parts
摘要： Laser Metal Deposition (LMD) of large parts is very challenging technology for aerospace industry. Due to high productivity of several kilograms per hour and nearly unlimited part size, this technology becomes competitive to traditional production technologies of casting, welding and rolling. One of the main problem of large parts manufacturing is the high distortion. Estimation of residual stresses and distortion is necessary to obtain required dimensional accuracy and prevent fracture of additively manufactured parts. Effects of layer-by-layer evolution of stresses and strains was studied by finite-element simulation. It was shown that distortion of axially symmetrical parts can be successfully predicted by the developed simulation procedure. It was established that the effect of increasing cylinder radius is to increase residual radial displacement and curvature of the sidewall. The highest tension hoop and axial stress amounted to 1.15-1.2 times of yield stress near the substrate. If deposited material have a weak ductility (e.g. titanium alloys) there is a high probability that the fracture could occurs in the sidewall near the substrate. Several experimental trials was carried out for validation of accuracy of developed simulation procedure. Shape of build parts was analysed by 3D laser scanner.
关键词： residual stress,laser metal deposition,distortion,finite element method.
更新于2025-09-12 10:27:22
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Prediction of Weld Interface Depth and Width at Optimum Laser Welding Temperature for Polypropylene
摘要： In this preliminary research, Through Transmission Laser Welding (TTLW) of polypropylene is systematically studied through finite element method (FEM) and response surface methodology (RSM) combined approach. The thermal field simulated by solving a three-dimensional transient heat diffusion equation using COMSOL Multiphysics. Statistical software Minitab v17 has been used to develop an experimental design as per central composite design. The objective of the work is in twofold. The first objective of the study aims to develop mathematical models to predict the weld interface depth (MD), weld interface width (MW) and maximum temperature (Tmax), primarily in terms of the process line-energy. The developed mathematical models are examined by analysis-of-variance (ANOVA) technique to check their adequacy. The second objective of the study is to establish an optimised combination of laser welding parameters (laser power, scanning speed and spot diameter) to prevent polypropylene thermal degradation. The desirable MD and MW conditions have been predicted for the established optimised set of laser welding parameters. The results from this preliminary investigation using a FEM approach, can provide the basis for future design of experiments to help predict and obtain enhanced weld quality for polypropylene specifically and other polymer material system in general.
关键词： polypropylene,finite element method,response surface methodology,through transmission laser welding,weld bead dimensions
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE 31st International Conference on Microelectronics (MIEL) - Nis, Serbia (2019.9.16-2019.9.18)] 2019 IEEE 31st International Conference on Microelectronics (MIEL) - Arrays of Bowtie Plasmonic Nanoantennas for Field Enhancement in MOEMS
摘要： Many micro(nano)optoelectromechanical systems (MOEMS, NOEMS) require optical (generally, electromagnetic) field localization and concentration. These include for instance photocatalytic microreactors and labs on a chip, where it is necessary to localize optical energy into a fluidic channel. Other examples are chemical and biological sensors. Plasmonics on the other hand ensures field localization down to subwavelength volumes where evanescent fields can be tailored to the shape of minuscule channels in MOEMS and NOEMS. In this work we present a possible approach to the enhancement of optical fields in MOEMS and NOEMS systems where a linear array of plasmonic bowtie structures is used to concentrate the optical field into a dielectric channel. We perform our numerical simulations using the finite element method to analyze field distributions that can be achieved by the use of the bowtie antenna and the possibility to tailor these fields. We also analyze the influence of the shape of the coupled tips of bowties to the field distribution and frequency dispersion. We conclude that arrays of plasmonic bowties could be a promising candidate for optically assisted micro and nanofluidics.
关键词： field enhancement,bowtie nanoantennas,MOEMS,NOEMS,plasmonics,finite element method
更新于2025-09-12 10:27:22
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Efficient Finite Element Analysis of Axially Symmetrical Waveguides and Waveguide Discontinuities
摘要： A combination of the body-of-revolution and finite element methods is adopted for full-wave analysis of waveguides and waveguide discontinuities involving angular field variation. Such an approach is highly efficient and much more flexible than analytical techniques. The method is performed in two different cases: utilizing a generalized impedance matrix to determine the scattering parameters of a single waveguide section and utilizing periodic boundary conditions without sources. In order to confirm the validity and efficiency of both approaches, a few examples of axially symmetrical structures have been analyzed. The obtained results are compared to those obtained from commercial software and available in the literature.
关键词： generalized impedance matrix (GIM),periodic boundary conditions (PBCs),dispersion diagrams,metamaterials,Cylindrical waveguides,finite element method (FEM)
更新于2025-09-12 10:27:22
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Investigation of a passively Q-switched Raman laser at 1176?nm with Nd3+:YAG/Cr4+:YAG/YAG composite crystal and a coupled cavity
摘要： To reduce the thermal lens effect and increase the efficiency, a composite crystal of Nd3+:YAG/Cr4+:YAG/YAG and a coupled cavity structure were employed in our passively Q-switched YVO4-based Raman laser system. Both the simulation and the experiment results showed that the undoped YAG crystal bonded in the end-face of Cr4+:YAG crystal can speed up the heat transfer of Cr4+:YAG crystal and reduce the temperature difference between its side surfaces and the center significantly, and the coupled cavity structure can improve the laser performance, especially at high pump power. The maximum output power of Raman laser of 0.92 W at 1176 nm was obtained with an optical-to-optical efficiency of 11.51%. The corresponding repetition rate and the pulse width is 53.5 kHz and 3.22 ns, respectively.
关键词： Composite crystal,Passively Q-switched,Temperature field,Coupled cavity,Raman,Finite element method
更新于2025-09-12 10:27:22