摘要 :
Permanent magnet brushless DC (PMBL) motors are utilized in various applications. Design of PMBL motors mostly depends on experimental knowledge. In this paper an adaptive algorithm is proposed for PMBL motor design. Design equati...
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Permanent magnet brushless DC (PMBL) motors are utilized in various applications. Design of PMBL motors mostly depends on experimental knowledge. In this paper an adaptive algorithm is proposed for PMBL motor design. Design equations are derived from basic governing equations which may be applied to a variety of PMBL motors. Based on the equations, an innovative design flowchart is developed. Using the flowchart, a PMBL motor is designed as a case study. The physical parameters of the algorithm results are used to make a solid model analyzed by Finite Element Analysis (FEA). The model dimensions obtained from the algorithm are fine-tuned utilizing the FEA results. The FEA performance results, verifying the proposed algorithm, satisfy the design requirements. A fabricated motor having the same physical properties is tested and the performance parameters are measured and compared with the algorithm results and the FEA results.
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摘要 :
Permanent magnet brushless DC (PMBL) motors are utilized in various applications. Design of PMBL motors mostly depends on experimental knowledge. In this paper an adaptive algorithm is proposed for PMBL motor design. Design equati...
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Permanent magnet brushless DC (PMBL) motors are utilized in various applications. Design of PMBL motors mostly depends on experimental knowledge. In this paper an adaptive algorithm is proposed for PMBL motor design. Design equations are derived from basic governing equations which may be applied to a variety of PMBL motors. Based on the equations, an innovative design flowchart is developed. Using the flowchart, a PMBL motor is designed as a case study. The physical parameters of the algorithm results are used to make a solid model analyzed by Finite Element Analysis (FEA). The model dimensions obtained from the algorithm are fine-tuned utilizing the FEA results. The FEA performance results, verifying the proposed algorithm, satisfy the design requirements. A fabricated motor having the same physical properties is tested and the performance parameters are measured and compared with the algorithm results and the FEA results.
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摘要 :
Heat dissipation is a drastic issue to handle due to continued integration, miniaturization, compacting and lightening of equipment. Heat dissipaters are not only chosen for their thermal performance; but also for other design par...
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Heat dissipation is a drastic issue to handle due to continued integration, miniaturization, compacting and lightening of equipment. Heat dissipaters are not only chosen for their thermal performance; but also for other design parameters that includes weight, cost and reliability, depending on application. Present study has been taken place with circular perforated fin array with different perforation diameter. The main objective of this paper is the Numerical study to quantify Natural Convection heat transfer enhancement of fins array with different types of perforations like Circular, Elliptical, Square and Triangular based on its performance as well as with saving in material by mass. The variables for this natural convection cooling with the help of finned surfaces are geometrical parameters and positioning of perforation. In this study, the steady state heat transfer from the solid fin and perforated fin arrays are compared. The optimized parameters are analysed for better heat transfer coefficient. The increase in the heat transfer coefficient was achieved with perforated fins for area corresponding to 12mm perforation diameter, which shows better enhanced heat transfer coefficient as opposed to the solid fin array with saving in material by mass.
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摘要 :
Heat dissipation is a drastic issue to handle due to continued integration, miniaturization, compacting and lightening of equipment. Heat dissipaters are not only chosen for their thermal performance; but also for other design par...
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Heat dissipation is a drastic issue to handle due to continued integration, miniaturization, compacting and lightening of equipment. Heat dissipaters are not only chosen for their thermal performance; but also for other design parameters that includes weight, cost and reliability, depending on application. Present study has been taken place with circular perforated fin array with different perforation diameter. The main objective of this paper is the Numerical study to quantify Natural Convection heat transfer enhancement of fins array with different types of perforations like Circular, Elliptical, Square and Triangular based on its performance as well as with saving in material by mass. The variables for this natural convection cooling with the help of finned surfaces are geometrical parameters and positioning of perforation. In this study, the steady state heat transfer from the solid fin and perforated fin arrays are compared. The optimized parameters are analysed for better heat transfer coefficient. The increase in the heat transfer coefficient was achieved with perforated fins for area corresponding to 12mm perforation diameter, which shows better enhanced heat transfer coefficient as opposed to the solid fin array with saving in material by mass.
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This study constructs a safety assessment model for aviation, considering both warning and non-warning monitoring items. The model incorporates a novel metric that measures the likelihood of the blue standard, while accounting for...
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This study constructs a safety assessment model for aviation, considering both warning and non-warning monitoring items. The model incorporates a novel metric that measures the likelihood of the blue standard, while accounting for potential severity of monitored QAR data. A practical algorithm is offered for estimating the chance of events using the developed model. The model's effectiveness is corroborated through trials with QAR data based on A320 aircraft in China, and its advantages over traditional models are underscored. The safety assessment model holds significant utility for improving aviation safety control and decision-making.
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A solid-state battery is classified as a new battery technology generation with low potential hazards and high energy storage capacity. Even though the safety and capacity are excellent, the appearance of cracks at the solid elect...
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A solid-state battery is classified as a new battery technology generation with low potential hazards and high energy storage capacity. Even though the safety and capacity are excellent, the appearance of cracks at the solid electrode-solid electrolyte interface during both charging and discharging processes is still the main problem. Functionally Graded Material (FGM) is a strong candidate to substitute conventional solid materials of the battery constituents because it can significantly reduce the crack appearance due to dismissing the interface, which directly increases the reliability of the solid-state battery. This paper demonstrates finite element analysis of solid electrode-solid electrolyte FGM under tensile load. The FGM model was developed and simulated using a predefined field in Abaqus 2020 software to form a mechanical properties gradation. The model was examined numerically with various properties gradation numbers. The simulation results show that the FGM model with a larger gradation number generates a smoother stress distribution than a smaller one. Stress concentrations occur at fewer gradations with maximum stress at 1403 MPa; this becomes a source of crack initiation. The potential application of FGM for solid-state batteries (SSB) is then comprehensively discussed.
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We develop a three-dimensional, multi-scale, multi-physics lithium-ion battery model where in a mesoscale spherical particle model is considered an electrode particle domain and a single cell domain. The model is first compared wi...
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We develop a three-dimensional, multi-scale, multi-physics lithium-ion battery model where in a mesoscale spherical particle model is considered an electrode particle domain and a single cell domain. The model is first compared with the experimental voltage data measured at various discharge and charge current densities. The model predictions present key electrochemical and transport phenomena in lithium-ion batteries. Moreover, contours of solid electrode/electrolyte, temperature, and current density are presented under several different time to highlight insight into discharge and charge behaviors of lithium-ion batteries.
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摘要 :
We develop a three-dimensional, multi-scale, multi-physics lithium-ion battery model where in a mesoscale spherical particle model is considered an electrode particle domain and a single cell domain. The model is first compared wi...
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We develop a three-dimensional, multi-scale, multi-physics lithium-ion battery model where in a mesoscale spherical particle model is considered an electrode particle domain and a single cell domain. The model is first compared with the experimental voltage data measured at various discharge and charge current densities. The model predictions present key electrochemical and transport phenomena in lithium-ion batteries. Moreover, contours of solid electrode/electrolyte, temperature, and current density are presented under several different time to highlight insight into discharge and charge behaviors of lithium-ion batteries.
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摘要 :
Attenuation in soft solids are governed by power laws with non-integral exponents. Attenuation is a critical component for correctly modeling the wave propagation physics. For nonlinear waves, in particular nonlinear shear waves, ...
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Attenuation in soft solids are governed by power laws with non-integral exponents. Attenuation is a critical component for correctly modeling the wave propagation physics. For nonlinear waves, in particular nonlinear shear waves, it important to model the two competing effects accurately i.e. the generation of higher harmonics due to nonlinearity and its decay due to attenuation. Current numerical methods can model a linear attenuation power law using a single Kelvin or Maxwell body. In this work a collection of Maxwell bodies is used to model power laws with non-integral exponents, which is more general. Also, the nonlinear propagation of shear waves modeled using a system of hyperbolic PDEs together with the relaxation mechanisms is simulated using a custom high order finite volume method: piecewise parabolic method. The numerical method is validated using a set of power laws with different non-integral exponents, and also the dispersion incurred due to causality is validated. Further, attenuation law obtained from linear experiments of shear wave propagation in fresh porcine brain were used to validate the method. This method can be used to accurately determine the other unknown parameters like nonlinearity of soft tissues in brain, liver etc.
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This project aims to analyze the dielectric and electric shielding properties to ascertain the optimal shielding. Materials that have been applied range from being electrically non-conductive to conductive based on the application...
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This project aims to analyze the dielectric and electric shielding properties to ascertain the optimal shielding. Materials that have been applied range from being electrically non-conductive to conductive based on the application of them being either used as a conductor or as an insulator. This correlation had studied and analyzed in COMSOL Multiphysics software and variability of the capacitance and conductance for different blend of materials at different area fractions of the model that depends on the effective shielding of the EM waves respectively in the dielectric and electric shielding. However, electric and dielectric shielding serves for various purposes and are not directly comparable in terms of which is best. Amongst the materials that are available from the Software, a film made of Carbon nanotubes (CNTs) aerosol CVD; (nk 0.250-3.30 um) sized material produces the best shielding results for dielectric shielding and Copper, Nickel (solid, Annealed) blended material produces the best shielding results in case of electric shielding model.
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