Conjugate Conduction-Convection Heat Transfer for Water-Cooled High-Speed Flows

2008 ◽  
Author(s):  
William Engblom ◽  
Bruno Fletcher ◽  
Nicholas Georgiadis
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Conjugate Conduction ◽  
High Speed Flows

scholarly journals CONJUGATE CONDUCTION-FREE CONVECTION HEAT TRANSFER FROM A HORIZONTAL CYLINDER

2013 ◽  
Vol 36 (2) ◽  
pp. 155-166
Author(s):  
M. K. Bassiouny ◽  
F. M. Mahfouz ◽  
S. A. Wilson ◽  
Gamal H. Badawy
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Convection Heat Transfer ◽  
Horizontal Cylinder ◽  
Convection Heat ◽  
Free Convection Heat ◽  
Conjugate Conduction

Thermal Response Characteristics of Flat Plate Heated by High Temperature and High Speed Flow

2013 ◽  
Vol 448-453 ◽  
pp. 3316-3319
Author(s):  
Chuang Sun ◽  
Yang Zhao ◽  
De Fu Li ◽  
Qing Ai ◽  
Xin Lin Xia
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flat Plate ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Thermal Response ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient

According to the view of heat transfer, the process of the fluid flow with high temperature and high speed over a flat plate may be considered as the heat transfer process within a compressible thermal boundary layer. Based on the numerical results of thermal isolation assumption, combining the temperature comparison with modification method, a coupled method of convection heat transfer coefficient with temperature field of the plate is established, and the characteristics of the thermal response for the flat plate is dominated. Take some ribbed plates as instances, the convection heat transfer coefficient and temperature field of the plate are simulated through the provided coupled method. The results show that, not only the position and materials of the plate influence the convection heat transfer coefficient, but also the time.

scholarly journals Study on the Thermal Performance and Temperature Distribution of Ball Bearings in the Traction Motor of a High-Speed EMU

2020 ◽  
Vol 10 (12) ◽  
pp. 4373
Author(s):  
Yu Wang ◽  
Junci Cao ◽  
Qingbin Tong ◽  
Guoping An ◽  
Ruifang Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Thermal Performance ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Ball Bearings ◽  
Convection Heat ◽  
Rolling Bearings ◽  
Traction Motors

The transient thermal performance of rolling bearings affects the mechanical performance and system safety of traction motors. Most of the traditional empirical formulas used in temperature analysis have been simplified and cannot be completely applied to the calculation of heat generation and convection heat transfer coefficients. Based on the comparative analysis of finite element transient temperature and experimental data, this paper proposes a correction method of mathematical model and derives an accurate calculation formula for the heat generation and lubricant convection heat transfer coefficient of ball bearings applicable for the non-driving end in the traction motor of a high-speed EMU (Electric Multiple Unit). The accuracy of the results has been verified by durability experiment data. In addition, with changes in speed, radial load and other factors taken into account, we have analyzed the influence of these time-varying factors on ball bearing temperature, as well as the temperature distribution law of each component in a grease-lubricated bearing, in a bid to lay a foundation for follow-up research on the heat transfer laws of traction motors and rolling bearings.

scholarly journals Influence of Vacuum Level on Heat Transfer Characteristics of Maglev Levitation Electromagnet Module

2020 ◽  
Vol 10 (3) ◽  
pp. 1106 ◽  
Author(s):  
Yiqian Mao ◽  
Mingzhi Yang ◽  
Tiantian Wang ◽  
Fan Wu ◽  
Bosen Qian
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Speed ◽  
Heat Dissipation ◽  
Aerodynamic Drag ◽  
Convection Heat Transfer ◽  
Total Heat ◽  
Heating Process ◽  
Convection Heat ◽  
Vacuum Level

The vacuum tube transportation (VTT) system has been a promising direction of future transportation. Within this system, a high-speed maglev travels in a low-vacuum environment to reduce aerodynamic drag. However, the heat dissipation of on-board heating devices will be compromised under low-vacuum conditions, and the device performance may thus be lowered. This study investigates the low-vacuum conjugate heat transfer characteristic of a levitation electromagnet module of a maglev using an experimentally verified numerical method. During the heating process, the surface temperature distribution of the levitation electromagnet, and the temperature and velocity characteristics of the flow field are examined. It is found that, as the vacuum level increases from 1.0 atm to 0.1 atm, the total heat dissipating from the levitation electromagnet module is decreased by 49% at 60 min, the contribution of convection heat flux over the total heat flux is decreased from 49% to 17%, and the convection heat transfer coefficient of the levitation electromagnet is decreased by 89%. This study can provide an efficient numerical model for low-vacuum heat transfer study on a VTT system as well as help the evaluation and optimization of low-vacuum maglev thermal management systems.

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