Search

Your search keyword '"Yan, Zhongming"' showing total 93 results
Start Over Author "Yan, Zhongming"
93 results on '"Yan, Zhongming"'

53. Heat Dissipation Design Based on Topology Optimization and Auxiliary Materials

Author

Chen, Jiawei, Yan, Zhongming, Qiao, Yang, Lin, Feihong, Wang, Yu, and Zhou, Hongcheng

Abstract

In this paper, a variable density topology optimization method is used to design a high thermal conductivity path structure for efficient heat dissipation. The temperature and stiffness in the module volume are taken as the objective function. Simulations are carried out to compare with a high-power electronics device heat dissipation. The heat dissipation performance (HDP) of structures optimized topologically is further enhanced through the use of auxiliary materials, including highly thermally conductive coating material and phase change material (PCM). The efficient heat dissipation of the constructed topology optimization model and the effectiveness of the proposed method are verified.

Published
2024
Full Text
View/download PDF

79. Analysis and Evaluation of Three-Stage Twisty Octapole Field Electromagnetic Launcher

Author

Wang Yu, Li Haitao, Zhu Yingwei, Yan Zhongming, and Chen Weirong

Subjects
Physics, Nuclear and High Energy Physics, Projectile, Rotation around a fixed axis, Torsion (mechanics), Mechanics, Condensed Matter Physics, law.invention, Magnetic field, Transverse plane, Classical mechanics, law, Eddy current, Torque, Multipole expansion
Abstract

In this paper, we propose an improved launch mode called multistage twisty multipole electromagnetic launcher. The twisty multipole magnetic field configuration is resolved, and the group power supply module is considered. The induced eddy current of the projectile is considered, and the analysis of electromagnetic force and torque has been performed. A full 3-D transient motion simulation with multiple degrees of freedom is carried on the three-stage twisty octapole field electromagnetic launcher. The simulation results indicate that the magnetic torque of rotational motion is impressively large and the transverse displacement of the projectile is much little. The torsion option of multistage pole coils makes little influence on axial acceleration force and exit velocity comparing with the appositional configuration. The theoretical analysis and numerical simulations indicate that the projectile is accelerated with spinning motion about its axis which could keep the projectile fly stability. We suggest this launch mode could be applied in the evacuated tube transportation vehicle.

Published
2012

90. Experimental Study of Thrusts of a Cylindrical Linear Synchronous Motor With One or More YBCO Bulk Magnets as the Excitation System.

Author

Duan, Wanqing, Yan, Zhongming, Luo, Wenbo, Zhang, Peixing, Gui, Zhixing, Wang, Zhiquan, and Wang, Yu

Subjects
*THRUST, *LINEAR synchronous motors, *MAGNETIC properties of yttrium barium copper oxide, *EXCITATION systems in electric machinery, *MAGNETIZATION measurement
Abstract

The thrusts of a cylindrical linear synchronous motor with one or more YBCO bulk magnets as the excitation system were measured for the first time and are presented in this paper. The YBCO bulk magnets are cylindrical with a diameter of 30 mm and a height of 18 mm. The armature of the motor is three phase and made of copper wire coils. The inner diameter of the armature is 40 mm. At the temperature of 77 K and a radial gap of 5 mm between the armature and the excitation system, with a charging magnetization current of 40 A for one YBCO bulk magnet and the RMS value current of 10 A for the armature coils, a peak thrust of 27.2 N was measured. Effects of armature current, charging magnetization current, running time, and magnetizers were also studied. When the excitation system had two or three full magnetized YBCO bulk magnets and magnetizers between them, the thrust was nearly two or three times as strong as the thrust of one YBCO bulk magnet under the same conditions. [ABSTRACT FROM PUBLISHER]

Published
2015
Full Text
View/download PDF

92. Design and Testing of a Novel Inductive Pulsed Power Supply Consisting of HTS Pulse Power Transformer and ZnO-Based Nonlinear Resistor.

Author

Wu, Rui, Wang, Yu, Yan, Zhongming, He, Zhengyou, and Wang, Liang

Subjects
INDUCTIVE power transmission, HIGH temperature superconductivity research, HIGH temperatures, ELECTRIC resistors, AMPLITUDE modulation
Abstract

Higher energy density makes inductive energy storage more promising than capacitive storage for pulsed power supplies in industrial and military fields. To realize high amplitude of pulsed current and relieve stress of opening switch, this paper proposes a novel inductive pulsed power supply consisting of high-temperature superconducting pulse power transformer and ZnO-based nonlinear resistor. First, working processes and laboratory setup are described in detail. Then, simulation using the software SIMPLORER is built to show major pulse characteristics and comparisons of two different nonlinear resistors. For verifying the feasibility of this mode, high-current testing is carried out and the results show that large amplitude of pulsed current 3 kA with energy transfer efficiency 60% is achieved, and the ZnO-based nonlinear resistor can help to limit the voltage of the opening switch to a small constant below its clamping value as current is interrupted. [ABSTRACT FROM PUBLISHER]

Published
2013
Full Text
View/download PDF

93. Design and Experimental Realization of a New Pulsed Power Supply Based on the Energy Transfer Between Two Capacitors and an HTS Air-Core Pulsed Transformer.

Author

Wu, Rui, Wang, Yu, Yan, Zhongming, Luo, Wenbo, and Gui, Zhixing

Subjects
ENERGY transfer, ELECTRIC power, ELECTRIC transformers, ELECTRIC machinery, CAPACITORS
Abstract

The application of pulsed power technology in the industrial and military fields requires a pulsed power supply as the large current generator. Based on theoretical analysis, it can be found that the traditional capacitor-based pulsed power supply may generate a large residual current during the discharging phase, which results in an adverse influence on the output current and energy transfer efficiency. To obtain higher energy transfer efficiency by eliminating the residual current, a new pulsed power supply based on the energy transfer between two capacitors and a high temperature superconducting (HTS) air-core pulsed transformer is proposed and a small-scale experiment is carried out under the different initial conditions. The experimental results show that a large pulsed current of 3.79 kA within 5 ms can be realized with the initial voltage 1.3 kV, whose energy transfer efficiency exceeds 65%. Finally, the feasibility of this new pulsed power supply is verified and it provides some guidance for future work. [ABSTRACT FROM PUBLISHER]

Published
2013
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results