上海工程技术大学学报

Simulation and experimental of temperature field of hybrid magnetizing magnetic gear composite motor

LIU Rui, ZHU Zina, ZHANG Bangjing, CHEN Saixuan

2023, 37(3): 215-221. doi: 10.12299/jsues.22-0090

Abstract:
The temperature field of a hybrid magnetizing magnetic gear compound motor, the copper, iron and eddy current losses of the motor were obtained by simulation of the magnetic gear compound motor, and the results were set as the heat source of temperature field simulation, and the transient thermal analysis of the simplified magnetic gear compound motor model was carried out. The temperature field distribution and temperature variation with time of the hybrid magnetizing magnetic gear composite motor were obtained. By setting up an experimental platform for temperature test, the temperature rise curve of each part of the motor with time change was obtained through calculation, simulation and test. It can be seen that the highest temperature point in the magnetic gear composite motor is in the stator winding part, and the temperature within the safe range, which will not affect the motor.or.

[Abstract](130) [FullText HTML] (266) [PDF 2934KB](477)

Simulation analysis of factors affecting transmission efficiency of Maxwell-based MCR-WPT system

ZHANG Weifang, ZHANG Hua, YUAN Tianchen, WEI Lili

2023, 37(3): 222-227. doi: 10.12299/jsues.22-0373

Abstract:
Coupled mode theory and equivalent circuit model were used to conduct a theoretical analysis of a typical magnetic resonance wireless power transmission system, and the theoretical relationship between transmission efficiency and coupling coefficient between resonant coils was obtained. The Maxwell simulation platform was used to construct a closed coil model, coil's parameter was scanned, and resonant coil was simulated and analyzed, and the influence of the coil's structural parameters (including the number of coil turns, turn spacing, and inner diameter) and the spatial distance between coils on the system transmission efficiency were obtained. The results show that increasing the number of coil turns can effectively improve the system transmission efficiency. The optimal turn spacing and inner diameter of the coil maximize the system transmission efficiency. Appropriate changes in the spatial distance between coils have a significant impact on the system transmission efficiency. The analysis results can provide a theoretical basis for subsequent optimization of magnetic resonance coils.

[Abstract](150) [FullText HTML] (33) [PDF 1066KB](179)

Study on fixed-time synchronization for permanent magnet synchronous motor with parameter uncertainties

WANG Kejie, TONG Dongbing, CHEN Qiaoyu, SUN Yuqing, MAO Qi

2023, 37(3): 228-232. doi: 10.12299/jsues.22-0139

Abstract:
The fixed-time synchronization problem was solved for permanent magnet synchronous motor (PMSM) with parameter uncertainties. Based on the fixed-time control theory and Lyapunov stability theory, the new fixed-time synchronization scheme was designed for PMSM with uncertain parameters. According to the adaptive control method and inequality technique, the fixed-time synchronization controller was obtained, which makes the PMSM with uncertain parameters achieve fixed-time synchronization in a short time, and the upper bound of the synchronization time is only related to the system parameters. The simulation and comparison results confirmed the validity of the proposed results.

[Abstract](95) [FullText HTML] (44) [PDF 849KB](260)

Influence of ellipticity and tube inclination angle on thermal performance of tube-fin heat exchanger

WANG Zhoupeng, DENG Shengxiang

2023, 37(3): 233-239. doi: 10.12299/jsues.22-0186

Abstract:
The model of tube-fin heat exchanger was established, and thermal performances of tube-fin heat exchanger with different ellipticities and tube inclination angles were analyzed by 3D CFD sfotware when the Re was 500~1600. The effects of ellipticities (0.45~0.85) and tube inclination angles (0^o~45^o) on flow and heat transfer characteristics, colburn factor j, friction factor f and efficiency index j/f of tube-fin heat exchanger were analyzed. The results show that j and f decrease with the increase of Re, while j/f increase with the increase of Re and tend to be gentle. Proper tilt angle is beneficial to generate more turbulence and strengthen convective heat transfer. When the ellipticity of tube-fin heat exchanger is 0.75 and the inclination angle of the tube between 15^o and 25^o, the heat transfer and fluid flow characteristics are the most favorable.

[Abstract](113) [FullText HTML] (49) [PDF 1296KB](16)

Research on axial U-shaped water channel cooling structure of hub motor

LIU Zhuo, YAN Yecui

2023, 37(3): 240-246. doi: 10.12299/jsues.23-0183

Abstract:
In order to solve the problems of heat dissipation difficulty and high temperature of end windings in the operation of electric vehicles, a new type of axial U-shaped water channel cooling structure design was proposed by taking an external rotor hub motor of electric vehicles as the research object. Firstly, the magnetothermal coupling simulation model of the hub motor was established, the temperature field distribution of the motor was obtained through the motor loss analysis, and the design and fluid-thermal coupling analysis of the axial U-shaped waterway were carried out. The results show that the use of U-shaped cooling channel could effectively improved the high temperature inside the motor, especially the high temperature problem of the end winding, and the temperature rise was reduced by 28.7%.

[Abstract](102) [FullText HTML] (37) [PDF 2513KB](17)

Effective potential and stable circular orbits in magnetized Schwarzschild spacetime

LIU Wenfang, ZHOU Naying, ZHANG Hongxing, SUN Xin

2023, 37(3): 247-254, 334. doi: 10.12299/jsues.22-0338

Abstract:
An effective potential in the equatorial plane was used to study the circular motion of charged particles near the Schwarzschild black hole immersed into an external magnetic field. It is found that no stable circular orbits exist for some angular momenta and small magnetic fields. However, the stable circular orbit easily occurs and has small radius when the magnetic induction increases. The radius of stable circular orbit increases with an increase of the angular momentum. The relation between the angular momentum and a radial distance can show the features of circular orbits, as the relation between the effective potential and the radial distance can.

[Abstract](88) [FullText HTML] (47) [PDF 2189KB](16)

Research on path planning of mobile robot based on improved multi-step ant colony algorithm

MA Teng, MAO Jian

2023, 37(3): 255-262. doi: 10.12299/jsues.22-0174

Abstract:
Improved multi-step ant colony algorithm was proposed to solve the problems of traditional ant colony algorithm in path planning, such as poor practicability, slow convergence speed and local optimization. All the direct nodes in the field of view of the mobile robot for the improved algorithm were taken as the next optional node set, the multi-step moving method was used to find the next node in any direction and at any step length, and the optimization efficiency of the algorithm and the diversity of path planning was improved. The initial pheromones among nodes were unevenly distributed according to the distance between each node and the connecting line between current and target node, the blindness of ant colony search in the initial stage of the algorithm was reduced. By increasing the pheromone update gap between the high-quality path and the low-quality path through the path length, the heuristic function and the convergence speed of the algorithm was improved. The simulation results show that the improved algorithm has the advantages of short length, high smoothness and less steps, which are more in line with the actual needs of mobile robots. The convergence speed and the effect of path planning are significantly improved.

[Abstract](152) [FullText HTML] (38) [PDF 1277KB](26)

Effect of two-sphere particles on flow field structure of flat plate boundary layer

DING Mingjie, DONG Lin, BAN Runze, FENG Kaibin

2023, 37(3): 263-271. doi: 10.12299/jsues.23-0139

Abstract:
To comprehend the flow structures surrounding particles within the boundary layer, particle image velocimetry (PIV) technique was employed to measure the flow field characteristics around particles of three distinct diameters and six different spacings within the Reynolds number range of 500 to 2000. The analysis results of the flow field characteristics reveal that with escalating fluid velocity and particle diameter, the vortex region behind the particles progressively intensified, exhibiting three distinctive modes: a singular vortex, mirror-symmetric vortices, and large-small oppositely rotating vortices. Among the observed experimental particles, the vortex region behind 10 mm particles displayed the most pronounced characteristics. However, upon reaching a certain threshold of particle spacing, the enhancement of the vortex region behind the particles ceased with further increases in spacing. These research findings serve as experimental evidence toward further elucidating the flow structures around particles within the boundary layer.

[Abstract](75) [FullText HTML] (36) [PDF 2814KB](12)

Asynchronous sliding mode control for Markovian jumping systems in finite-time intervals

WEI Changjiang, CHEN Qiaoyu

2023, 37(3): 272-280. doi: 10.12299/jsues.23-0067

Abstract:
The problem of asynchronous sliding mode control in finite-time intervals was studied for Markovian jumping systems. A mode-dependent sliding mode surface function was designed based on the hidden Markov model for the unmeasurable non-synchronization phenomenon. A sliding mode controller was designed to drive the state trajectory of the system to the specified sliding mode surface in a specified finite-time. Through the finite-time analysis method, the finite-time boundedness criterion of sliding mode dynamics in the arrival stage and sliding motion stage was gained, sufficient conditions for the solution of the asynchronous controller gain matrix were obtained. Finally, a single-link robot arm model was used to demonstrate the effectiveness of the results.

[Abstract](117) [FullText HTML] (37) [PDF 1363KB](21)

Comparison of Fe-Ti binary system thermodynamic assessments

JIN Zongxiao, SU Yu, LI Jun, YANG Huiwen

2023, 37(3): 281-289. doi: 10.12299/jsues.22-0254

Abstract:
As a subsystem of multi-principal-elements Fe alloys and multi-principal-elements Ti alloys, the thermodynamic properties of the Fe-Ti binary system are the basis for expanding it to multi-dimensional applications. By using CALPHAD method, five of the most representative Fe-Ti binary system assessment research articles in recent decades were selected and the calculation conclusions of these research were reproduced. Meanwhile, the dissimilarities of the thermodynamic modeling of stable phases of different assessments and the impact on the final evaluation results were compared, and some problems in the evaluation were pointed out.

[Abstract](99) [FullText HTML] (56) [PDF 1592KB](15)

Aggregation-Induced emissive molecule with large stokes shift based on naphthalimide and triphenylamine

JIN Yitong, HUANG Wenling, JIANG Na, ZHOU Huimin, QU Yi

2023, 37(3): 290-295. doi: 10.12299/jsues.22-0341

Abstract:
Aggregation-induced emission (AIE) phenomenon is one of the research highlights in the field of optoelectric materials. However, the most advanced AIE materials emit the short wavelength fluorescence in blue to green region. The efficient energy transfer process was achieved via overlay the spectra of chromophores, which can construct the AIE-active molecule (NIPTPACN) with large Stokes shift. The 4-phenylnaphthalimide (NIP) with blue AIE fluorescence developed in our lab was selected as the energy donor and the β-cyanoethenyltriphenylamine (TPACN) with red fluorescence was selected as the acceptor. The obtained NIPTPACN can output the strong red fluorescence centered at 608 nm in aqueous solution (aggregated state) under excitation at 365 nm. The Stokes shift of NIPTPACN reaches 248 nm and the fluorescent intensity of NIPTPACN at 608 nm is 82.6-fold than the one of the solo TPACN fluorophore. This work successfully constructs an AIE-active molecule with long emission wavelength and large Stokes shift, which can provide the new strategy based on the fluorescence resonance energy transfer (FRET) mechanism.

[Abstract](74) [FullText HTML] (41) [PDF 1674KB](14)

Study on ultimate bearing capacity of CHS X-joints strengthened with CFRP

YANG Yong, HE Xiang

2023, 37(3): 296-304. doi: 10.12299/jsues.23-0109

Abstract:
In order to study the influence of carbon fiber reinforced plastic (CFRP) on the X-shaped circular steel tubular joints, the ABAQUS finite element software was redeveloped. The VGM model was compiled into the VUSDFLD subroutine by Fortran language. The finite element analysis of 90 joint models was carried out, and the effects of the ratio of the outer diameter of the branch to the main pipe β, the ratio of the diameter to the thickness of the main pipe γ, the ratio of the length of CFRP to the diameter of the main pipe L, and the number of CFRP layers n on the bearing capacity of the joints were studied. The results show that CFRP can reduce the stress concentration of the joint and improve the bearing capacity of the joint. The cracking of the joint will occur at the weld root where the inner side of the saddle point weld of the intersecting line intersects with the branch pipe. With increasing of the load, the crack develops from the weld saddle point along the intersecting line to the crown point. Parameters analysis of the joint show that with the increasing of γ, the ultimate bearing capacity of the joint decreases gradually, with the increasing of β, the ultimate bearing capacity of the joint increases gradually, with the increasing of n and L, the ultimate bearing capacity of the joint will increase. For the failure of the joint occured in the weld, the formula for the weld bearing capacity of the CFRP strengthened X-shaped circular steel tube intersecting joint was proposed. Compared with the finite element results, it can be found that the results of the formula fitted are unsafe when the wall thickness of the main pipe of the joint is small and the outer diameter of the branch pipe is large.

[Abstract](76) [FullText HTML] (30) [PDF 1263KB](10)

Effect of citric acid on catalytic activity of molybdenum disulfide catalyst for hydrogen evolution reaction

FENG Rumeng, LIANG Wei, CHEN Lu, YANG Shixin, DENG Ruyi, ZHANG Xiaoqing, LI Wenyao

2023, 37(3): 305-310. doi: 10.12299/jsues.22-0340

Abstract:
Thioacetamide with stable properties and strong reducing ability was selected as sulfur source and reducing agent to prepare MoS₂ catalyst by simple hydrothermal method. The influence of different amounts of citric acid on its electrochemical performance was investigated. The morphology and microstructure were characterized by SEM and TEM, electrochemical methods including CV, LSV and Tafel were used for characterization. The results show that the addition of citric acid could increase the electrochemical active surface area of MoS₂ catalyst and enhance the hydrogen evolution reaction (HER) catalytic activity of MoS₂ catalyst.

[Abstract](85) [FullText HTML] (32) [PDF 1642KB](14)

Carbon emission analysis of sewage treatment based on CiteSpace knowledge map

LUO Zexu, SHU Shihu, ZHU Yanping, CHEN Zhihui, YANG Zhongkan

2023, 37(3): 311-317. doi: 10.12299/jsues.23-0140

Abstract:
To comprehensively analyze the development and changes in carbon emissions associated with sewage treatment in China over the past two decades, key areas of focus, evolving trends, and the other pertinent aspects related to carbon emissions within China's domestic sewage treatment sector were analyzed based on journal articles sourced from the CNKI database and the CiteSpace knowledge mapping tool. Approaches to sewage treatment plant construction and updates to treatment processes were further discussed, and the methods and strategies of carbon neutrality in sewage treatment plants in future were summarized. The future research on carbon emissions in sewage treatment should be carried out from three aspects: enhancing collaboration among various universities, expediting the transformation of sewage treatment plants, and deepening research on treatment processes.

[Abstract](84) [FullText HTML] (34) [PDF 1536KB](17)

Influence of perceived value on consumers' purchase intention of personalized customized clothing

LI Shuang, LI Pei

2023, 37(3): 318-325. doi: 10.12299/jsues.22-0203

Abstract:
In order to study the relationship between perceived value and purchase intention in customized clothing, four independent variables were proposed, namely emotional value, functional value, social value and self-actualized value, and a theoretical model was built with satisfaction as the mediating variable and word of mouth as the moderating variable. Factor analysis, correlation analysis and regression analysis were used for empirical analysis. The results show that emotional value, functional value, social value and self-actualized value have positive effects on purchase intention. Satisfaction plays an intermediary role between emotional value, functional value and purchase intention. Word of mouth plays a moderating role between emotional value, functional value, social value and satisfaction. The research results will enrich the theory of the influence of perceived value on consumers' purchase intention, and have guiding significance for enterprises to understand consumers' personalized customized experience.

[Abstract](170) [FullText HTML] (75) [PDF 680KB](27)

Research on incentive mechanism under multi-demand-side cooperation in logistics service supply chain

HU Renjie, ZHU Weiping, CHEN Yalan, HE Yuxiu

2023, 37(3): 326-334. doi: 10.12299/jsues.23-0121

Abstract:
Based on the theory of common agency, incentive models for sequential cooperation mechanisms and alliance cooperation mechanisms were constructed, and simulation analysis was conducted. Research result show that under the sequential cooperation mechanism, the logistics service demander signs contracts with the logistics service integrator, and the party who signs with the logistics service integrator first is likely to be at a disadvantage. Under the alliance cooperation mechanism, logistics service demanders sign contracts with logistics service integrators, and the upper limit of the optimal effort level provided by logistics service integrators is higher than the upper limit of the optimal effort level provided by them under the sequential cooperation mechanism.

[Abstract](97) [FullText HTML] (42) [PDF 1768KB](16)

2023 Vol. 37, No. 3