Physical Field Model Research Articles

Automatic Tea Ceremony Teapot Robotic Arm Design Based on TRIZ Principle

With the accelerated pace of modern society, there is a contradiction between the tedious steps of traditional tea ceremony and the convenient lifestyle. In order to solve this problem, this study applies the TRIZ theory to optimize the design of the fully automatic tea ceremony teapot robot arm. Through the "nine-screen method", the traditional tea-making process was comprehensively analyzed, the key steps were identified, and the cultural significance and technical requirements of each step were discussed in depth. Using the "technical contradiction matrix" and "physical contradiction" analysis, the potential contradictions in the tea-making process were revealed, and the "physical field model" was applied to construct the problem model and explore the possible solutions. The problem model was constructed by applying the "Physical Field Model", and possible solutions were explored. The study proposes a fully automated tea art teapot robotic arm design program that integrates several key technology modules such as heating and temperature control, plane movement, lid operation, and pouring and dispensing of tea. The program ensures the quality of tea soup and the experience of traditional tea ceremonies through the well-designed robotic arm structure and improves the efficiency of tea brewing at the same time. The structural safety of the design scheme is verified by stress analysis of the connecting plate of the robotic arm and the connecting plate of the teapot base. Finally, the feasibility and effectiveness of the proposed scheme are verified through kinematic analysis, prototype testing, and user experience evaluation. This study is of great practical significance for the modernization and transformation of the traditional tea ceremony and also provides a reference for the automation of other traditional crafts. With the continuous progress of technology, we expect more innovative products combining traditional culture and modern technology to appear in the future so that traditional art can be revitalized in modern society.

Multi-objective optimization of a wet electromagnet-driven water hydraulic high-speed on/off valve for underwater manipulator in deep sea

Water hydraulic high-speed on/off valves (WHSVs) have the potential to replace the traditional oil hydraulic valves to be used in underwater hydraulic manipulators (UHMs) in the deep-sea environment due to their environmental friendliness, strong anti-pollution ability, and good sealing property. In this paper, we develop and optimize a novel wet electromagnet-driven WHSV to enhance its suitability for UHMs. Firstly, an accurate equivalent magnetic model of the WHSV is derived, considering the leakage flux and nonlinear characteristics. This magnetic model is combined with other physical field models to accurately describe the dynamic behavior of the WHSV and provide a comprehensive simulation framework. Then, the multi-objective optimization and decision-making methods are combined to optimize and determine the structural parameters of the WHSV, achieving a balance between rapid response and light mass. Finally, a WHSV prototype is manufactured and tested based on the optimized structural parameters. Experimental results indicate that the WHSV achieves opening and closing times of 1.63 ms and 1.22 ms, respectively, with the electromagnetic components weighing 75.5 g. These results show a maximum deviation of 7.4 % from the optimization results (1.52 ms, 1.31 ms, 71.6 g). Moreover, the deep-sea simulation test verifies the prototype functionality under a high-pressure condition (110 MPa).

Effect of heat conduction on viscoelastic lubricant behavior during heat-assisted magnetic recording (HAMR): A numerical study

Heat-assisted magnetic recording (HAMR) is one of the critical technologies to overcome the areal density limitations of hard disk drives. In order to reveal the behavior of viscoelastic lubricants under HAMR conditions, the coupled physical field model of disk Fourier heat conduction model and viscoelastic lubricant model is established. The effects of Fourier heat conduction model and Gaussian distribution model on the disk temperature distribution and viscoelastic lubricant behavior are investigated. The lubricant deformation calculated by the Fourier heat conduction model is more accurate. The laser power overshoot method is proposed to improve the efficiency of HAMR writing process. The lubricant recovery ratio calculated by the Fourier heat conduction model is greater than that calculated by the Gaussian distribution model. The smaller the laser radius is, the greater the deformation of the lubricant is, and the lower the recovery ratio is.

Analysis of the correlation between GIS partial discharge current waveform and charge quantity with UHF signals

The Ultra-High Frequency (UHF) method, as a crucial technology for online GIS monitoring, struggles with the issue of being unable to accurately reflect the number of partial discharges, which poses a significant challenge for this technique. To examine the relationship between partial discharge waveforms, charge quantity, and UHF signals, a physical field model of partial discharge is developed using finite element simulation software, allowing a comparison of the peak-to-peak values of UHF signals with the parameters of the partial discharge current. Research demonstrates a roughly linear relationship between the peak-to-peak values of UHF signals and the magnitude of the partial discharge current but no definitive connection with the discharge quantity. These significant findings guide the quantitative detection of partial discharges in electrical equipment using the UHF method.

Ultrasonic propagation characteristics of partial discharge in oil-impregnated paper traction transformer

Partial Discharges (PDs) are a significant factor in reducing the insulation life of traction transformers. In recent years, the Acoustic Emission (AE) method has become the most advanced method for detecting PD signals in transformers. The AE method utilizes AE sensors placed on the transformer tank to detect ultrasonic signals emitted by PD and determine the Time Of Arrival (TOA) of the head wave. The windings and cores of a traction transformer consist mainly of metal, which greatly affects the propagation of PD ultrasonic waves. This paper establishes a 110 kV “pressure acoustic, transient” physical field model of the traction transformer with dimensions of 4.63 × 1.48 × 2.84 m3. The model is used to carry out the PD pressure acoustic physical field simulation study of the traction transformer, to clarify the physical characteristics of the ultrasound of the PD defects, and to establish observation points on the transformer tanks to receive ultrasonic time-domain waveforms for PD detection. The simulation results indicate that PD ultrasonic waves exhibit complex propagation characteristics, including reflection, refraction, and reverberation, as they pass through the windings and cores to the observation points. The TOA of the head wave in the ultrasound time-domain waveform is indicated by the first maximum value of the wave crest line. Finally, this paper proposes a multi-level localization method based on the AE method to determine which winding generates the PD in the large-scale traction transformer using only four dynamically moving observation points.

Time-Varying Cumulative Damage Recursive Method for Power Semiconductor Devices

Accurate simulation of power semiconductor devices failure process is one of the most important means to clarify the failure mechanism and evaluate the device reliability, which is induced by the associated internal temperature gradient acting on the mismatch of coefficients of thermal expansion between adjacent layers and internal temperature gradients. This paper investigates the microstructure change of the new and replaced modules using the CT scanner, which represents that the void distribution of the die-attach solder layer is an important factor to indicate the reliability status of the power semiconductor devices. A multiple physical field model combining time-varying cumulative damage recursive method is proposed to simulate the damage accumulation and the physical failure process based on mesh automatic updated method and material failure formula. The number of cycles to failure, thermal resistance, and junction temperature extracted from power cycling test results are used to validate the accuracy of the parameter variation. The physical outline of the voids is extracted to prove the consistency of the microstructure change. This method is intended for operational management and also provided the foundation for the design and development of power electronic devices with high power and high reliability.

A High-Precision Temperature Measurement Method Through Correcting Reflected Radiation Under High-Temperature Background

In this paper, a high precision correction method for temperature measurement errors due to reflected radiation under high temperature background is reported by applying calibration experiments. The correction theory governing the temperature measurement errors caused by reflected radiation is derived in principle, and the physical field model of temperature measurement is established for a ceramic blade in a high temperature furnace. The temperature measurement errors before and after the correction of the reflected radiation are analyzed through simulations, and the reflected radiation in the temperature measurement environment of the blade is calibrated. The experimental results show that the errors of monochromatic and colorimetric temperature measurements are decreased from 13.5% and 7.5% to 0.3% and 0.5%, respectively. The results indicate that the proposed method can significantly decrease the temperature measurement errors caused by reflected radiation.

Effect of Positive Bias and Pressure on Plasma Flow Characteristics in a Chemical Vapor Deposition Chamber

To better understand how positive bias and deposition pressure affect the plasma flow properties in the deposition chamber during the bias-enhanced MPCVD process, a two-dimensional axisymmetric model based on the discharge mechanism of pure H2 was constructed. The coupling process between different physical field models of the electromagnetic field, plasma, and temperature field in the MPCVD reactor is realized. We studied the influence of positive bias voltage and deposition pressure variation on microwave plasma flow characteristics in the deposition chamber. There was a bias voltage threshold phenomenon in the case of positive bias, and the suitable value range was narrow. Additionally, with the increase in the deposition pressure, the electron temperature in the deposition chamber tends to increase locally and reaches its maximum value when the pressure is approximately 30 torr. It provides new ideas and guidance for optimizing the process parameter setting of the bias-enhanced MPCVD process.

A Fast Calibration Method for Sensors of Atmospheric Detection System

To meet the needs of a large number of high-altitude meteorological detections, we need to perform fast, high-precision, and high-reliability calibrations of the sensors in the atmospheric detection system (ADS). However, using the traditional method to calibrate the sensor with high precision often takes a lot of time and increases the cost of workforce and material resources. Therefore, a method for realizing fast sensor calibration under the current system hardware conditions is required. A physical field model of Tube–Air–ADS is proposed for the first time, and the transfer function is obtained by combining the system identification, which provides the possibility for dynamic analysis of the calibration system. A Multi-Criteria Adaptive (MCA) PID controller design method is proposed, which provides a new idea for the parameter design of the controller. It controls the amplitude and switching frequency of the controller’s output signal, ensuring the safe and stable operation of the calibration system. Combined with the hardware parameters of the system, we propose the Variable Precision Steady-State Discrimination (VPSSD) method, which can further shorten the calibration time. Comparing and analyzing the current simulation results under Matlab/Simulink, the proposed MCA method, compared with other PID controller design methods, ensures the stable operation of the calibration system. At the same time, compared with the original system, the calibration time is shortened to 47.7%. Combined with the VPSSD method, the calibration time further shortens to 38.7 s.

Modeling of physical fields by means of the Cosserat continuum

AbstractWe consider a special type Cosserat continuum and suggest analogies between quantities characterizing the stress–strain state of the continuum and quantities characterizing physical processes. Such an approach provides us with the ability to derive equations describing electricity, magnetism, and other physical phenomena. This study continues the line of our earlier research. In the present paper, we obtain equations that can be treated as a generalization of Maxwell's equations. The main difference between the proposed equations and classical Maxwell's equations is in the description of magnetic phenomena. In particular, we introduce the concept of a magnetic charge vector and show that this quantity, like the electric charge, satisfies the conservation law and the Gauss law. We are convinced that the magnetic charge vector is the most appropriate physical quantity to characterize the state of a magnetized body. In addition to modeling the electromagnetic field, we make assumptions about how the proposed model can describe the field corresponding to the strong interaction.

The effect of gas injection velocity and pore morphology on displacement mechanisms in porous media based on CFD approach

Because of the unique advantages such as easy miscibility, high temperature resistance and so on, hydrocarbon gas flooding has proved to be a promising technology for enhanced oil recovery in deep reservoirs. In order to reveal the potential mechanism of miscibility and displacement of crude oil and hydrocarbon gas, an innovative two-dimensional physical field model is constructed by coupling Navier-Stokes equations and mass transfer equation. Accordingly, the effect of gas injection velocity and pore morphology on fluid transport and miscibility properties is investigated based on computational fluid dynamics approach. The simulation results demonstrated that the residual oil (RO) content is lower at low gas injection velocity than that at high gas injection velocity due to the better miscibility of fluids. For pore morphology, the RO content increases with increasing pore throat ratio and pore throat angle, which are not related to the gas injection velocity. The blocked pore structure has a negative effect on hydrocarbon gas flooding, resulting in the higher RO content. In addition, the influence of the pore throat length on the RO content is related to the gas injection velocity, which means the RO content increases at low gas injection velocity and decreases at high gas injection velocity with increasing pore throat length.

Study on the mechanism of a femtosecond laser-induced breakdown of the deposited substrate mediated by aluminum nanoparticles in a vacuum

The mechanism of a femtosecond laser-induced breakdown of deposited substrates mediated by aluminum nanoparticles in a vacuum environment was studied. This model of optical breakdown mediated by aluminum nanoparticles includes the electromagnetic field model for the description of near-field enhancement of aluminum nanoparticles, the two-temperature model for the description of electron and lattice temperature of aluminum nanoparticles, and the plasma model for the description of the evolution of electron density in the deposited substrate. These three physical field models were fully coupled in this model. We defined a new modified dielectric function model to describe the dielectric function of aluminum nanoparticles, due to the strength of near-field enhancement depends on the size and morphology of nanoparticles. The near-field enhancement of different types of aluminum nanoparticles, the femtosecond laser breakdown threshold of deposited substrates, and the evolution of the lattice temperature of aluminum nanoparticles were investigated. The results showed that assembled aluminum nanoparticles can significantly reduce the femtosecond laser breakdown threshold of deposited substrates in a vacuum, and the lattice temperature of aluminum nanoparticle was lower than the melting point, under the irradiation of a single-pulse femtosecond laser with a wavelength of 800 nm and pulse width of 25 fs.

Definition of dependence between energy point parameters and energy field point parameters

It is suggested to consider a number of problems related to the geometric modeling of physical fields generated by point sources of energy. This study shows the ways of solving the optimization problems of determining the capacities of point sources of energy generating an energy field and their location on a plane at given potentials of points of this field in given places.

Investigation on Deposition Behavior of HVDC Water Cooling System Based on Electro-Mass Transfer-Velocity Coupling Model

The water cooling system plays an important role in the high-voltage direct current (HVDC) converter station. To reduce the leakage current among metal components, a certain number of platinum electrodes are installed at the distributary pipes. However, due to electric field distortion around the platinum electrode, over 66% faults of the cooling system are contributed by the frequently occurred sediment deposition on the platinum electrode. This paper proposed a method to predict the dynamic deposition behavior of the water cooling system through the built electro-mass transfer-velocity coupling model. Additionally, the deformation feedback effect of a sediment growth process is also included. An experimental water-cooling setup was established, and the simulated operation experiments were conducted to explore the deposition mechanism at first, then the mathematical coupling model was proposed to describe the corrosion and deposition characteristic. In addition, the arbitrary Lagrangian-Eulerian deformation method was adopted to count the feedback effect of the deposition product formation process on the multiple physical field model. The experiments and simulations were conducted to demonstrate the concept and verify the method. The results show that the proposed method can do well with the dynamic sediment deposition and radiator corrosion problem together. Meanwhile, the deposited sediment not only cause over 116-V voltage distortion around electrode but also induce another 3.2-μA leakage current in radiators. As a result, the voltage balance ability of the electrode would be seriously destroyed and aggravate the deposition situation.

Condition Monitoring in a Power Module Using On-State Resistance and Case Temperature

Power electronics are widely used in energy conversion systems due to their high efficiency. Finding and replacing the defective power electronic modules timely by monitoring the ageing state of devices can greatly improve the security of power converters and reduce the loss caused by the device failure. Packaging-related fatigue has been identified as one of the main causes of the failures of power electronic modules. This paper proposes a method to monitor the fatigue inside a module by identifying the increase of internal on-state resistance under a certain operation conditions due to the device packaging-related fatigue. Multiple physical field model results show that the junction temperature increases with the thermal resistance, which causes an increase in the on-state resistance. Therefore, the healthy state of power modules can be diagnosed by comparing the difference of the on-state resistance before and after ageing in the same case temperature, which can be measured directly. Experiments and simulations are conducted to demonstrate the concept and verify the method.

Effect of quality factor on frequency stability of filmbulk acoustic resonator oscillator

The loaded quality factor (QL) of the film bulk acoustic resonator(FBAR) oscillator and the quality factor (Q value) of FBAR are related to the frequency stability of FBAR oscillator. In order to study the effect of the two kinds of quality factors on the frequency stability, the multi physical field model of FBAR was established in the COMSOL multiphysics software. The parameters of the modified Butterworth-Van Dyke (MBVD) model were got by frequency domain simulation and model parameter fitting. A model of MBVD circuit was established in the ADS software, and Q value for different loss was obtained by the simulation of S parameters and computing the corresponding Q value with the Bode method. The Pierce-based oscillator was established and simulated with the harmonic balance, thus the phase noise was obtained by changing QL and Q, and the effect of the two factors on frequency stability was got. The results show that the frequency stability increased with the increase of QL and Q, Q decreased with the increase of different losses. If the Q is lower than 338, the effect of increasing QL to improve the frequency stability is poor. Using this kind of FBAR to construct oscillator will not meet the requirements of FBAR wireless communication RF front-end as the reference signal source and the readout circuit of FBAR sensor. This paper provides a reference for FBAR frequency reference design and FBAR sensor readout circuit.

Numerical modeling of physical fields in the process of drying of paper for corrugating by the infrared radiation

By using a numerical model, developed based on the proposed physical and mathematical models, we performed a numerical study of non-stationary temperature fields and moisture content of the process of infrared radiation drying of fluting. A distinctive feature of present study is a combined consideration of the kinetics of drying process, translucency to the IR radiation of the material using the approximations of the Burgers' models, gray medium and diffuse reflection of boundaries. Verification of the numerical model demonstrated a convergence of results of numerical modeling of the fluting surface temperature, duration and speed of its drying with the data of physical experiment within the range of 5 % on the interval of change in the square meter mass of dry fluting from 0.112 kg/m 2 to 0.2 kg/m 2 . It is substantiated that the developed numerical model makes it possible to define kinetic patterns and basic parameters required to intensify the process of drying and to design the appropriate equipment.

MASSLESS SCALAR FREE FIELD IN 1+1 DIMENSIONS I: WEYL ALGEBRAS PRODUCTS AND SUPERSELECTION SECTORS

This is the first of two papers on the superselection sectors of the conformal model in the title, in a time zero formulation. A classification of the sectors of the net of observables as restrictions of solitonic (twisted) and non-solitonic (untwisted) sector automorphisms of proper extensions of the observable net is given. All of them are implemented by the elements of a field net in a non-regular vacuum representation and the existence of a global compact Abelian gauge group is proved. A non-trivial center in the fixed-point net of this gauge group appears, but in an unphysical representation and reducing to the identity in the physical one. The completeness of the described superselection structure, to which the second paper is devoted, is shown in terms of Roberts' net cohomology. Some general features of physical field models defined by twisted cross products of Weyl algebras in non-regular representations are also presented.

Mathematical modeling of physical fields by the point-source method

The point-source method is used to model physical fields. The error of this method is estimated. The results of testing the method are reported, which confirm its efficiency.

Physical field models for pattern classification

Recent findings in pattern recognition show that dramatic improvement of the recognition rate can be obtained by application of fusion systems utilizing many different and diverse classifiers for the same task. Apart from a good individual performance of individual classifiers the most important factor is the useful diversity they exhibit. In this work we present an example of a novel, well performing non-parametric classifier design, which shows a substantial level of diversity with respect to other commonly used classifiers. Inspired by the mechanics of omnipresent physical fields like gravitational or electrostatic, we considered the data as particles carrying elementary units of charge. The charge has been presented as a source of the potential triggering attracting interaction among the data. This interaction has been reformulated as data matching procedure and developed into original classification technique where the unlabelled testing data are captured by the labelled training data and share their labels. In the extended model apart from the spatial data distribution we also exploit topology of class labels to devise repelling force as field action between differently labelled data samples. As we show introduction of the repelling force clearly smoothes the decision boundaries and improves performance while still preserving attractive diversity properties of the classification model. The paper covers extensive examples and visual interpretations of the presented techniques supported by the experimental work with established datasets and classifiers.