A quasi transient heat conduction model of heat transfer in fuel-coolant interaction in LMFBRs

1981 ◽  
Vol 66 (1) ◽  
pp. 1-5 ◽  
Author(s):  
P. Bhaskar Rao ◽  
Om Pal Singh ◽  
R. Shankar Singh
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Transient Heat Conduction ◽  
Conduction Model ◽  
Heat Conduction Model

scholarly journals Analysis of the Properties of Fractional Heat Conduction in Porous Electrodes of Lithium-Ion Batteries

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 195
Author(s):  
Xin Lu ◽  
Hui Li ◽  
Ning Chen
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Porous Electrodes ◽  
Transient Temperature ◽  
Measured Temperature ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Fractional Heat Conduction

Research on the heat transfer characteristics of lithium-ion batteries is of great significance to the thermal management system of electric vehicles. The electrodes of lithium-ion batteries are composed of porous materials, and thus the heat conduction of the battery is not a standard form of diffusion. The traditional heat conduction model is not suitable for lithium-ion batteries. In this paper, a fractional heat conduction model is used to study the heat transfer properties of lithium-ion batteries. Firstly, the heat conduction model of the battery is established based on the fractional calculus theory. Then, the temperature characteristic test was carried out to collect the temperature of the battery in various operating environments. Finally, the temperature calculated by the fractional heat conduction model was compared with the measured temperature. The results show that the accuracy of fractional heat conduction model is higher than that of traditional heat conduction model. The fractional heat conduction model can well simulate the transient temperature field of the battery. The fractional heat conduction model can be used to monitor the temperature of the battery, so as to ensure the safety and stability of the battery performance.

A Closure Model for Transient Heat Conduction in Porous Media

1999 ◽  
Vol 121 (3) ◽  
pp. 733-739 ◽  
Author(s):  
C. T. Hsu
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Transient Heat Conduction ◽  
Equation System ◽  
Interfacial Heat Transfer ◽  
Conduction Model ◽  
Average Scheme ◽  
Interfacial Transport ◽  
Closure Relations

Equations governing the transient heat conduction in porous materials consisting of solids and fluids of different thermal properties were derived with a volumetric average scheme under the assumption of nonthermal equilibrium. The derivation leads to a macroscopic two-equation system which requires the closure modeling of new unknown terms due to interfacial transport, namely, the tortuosity term and the interfacial heat transfer term. Closure relations were obtained from the microscopic equations for temperature fluctuation under quasi-steady assumption. The closure coefficients appeared in the closure relations then depend on the media geometry as well as thermal properties. To demonstrate these dependencies, the closure coefficient for the thermal tortuosity is evaluated based on the effective stagnant thermal conductivity model proposed by Hsu et al. (1995) for periodically packed cubes, and the coefficient for interfacial heat transfer based on a quasi-steady heat conduction of dispersed spheres immersed in fluids. The salient features as well as the applicability and limitation of the newly proposed transient heat conduction model were discussed.

Heat Transfer From a Moving and Evaporating Meniscus on a Heated Surface

2003 ◽  
Author(s):  
Satish G. Kandlikar ◽  
Wai Keat Kuan
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Heated Surface ◽  
Water Flow Rate ◽  
Transient Heat Conduction ◽  
Heat Transfer Process ◽  
Conduction Model ◽  
Experimental Heat ◽  
Experimental Heat Transfer

A stable meniscus is formed between a needle dispensing water over a heated circular face of a rotating copper block. The needle is offset from the axis of rotation and thus forms a moving meniscus. The water flow rate, heater surface temperature and the speed of rotation are controlled to provide a stable meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer rate is compared with the transient heat conduction model developed here. The results indicate that the transient heat conduction plays a major role in the heat transfer process from a moving meniscus. The study provides an important insight on the role of transient conduction around a nucleating bubble in pool boiling.

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