scholarly journals On heat transfer of weakly compressible power-law flows

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 2709-2718
Author(s):  
Botong Li ◽  
Liangliang Zhu ◽  
Liancun Zheng ◽  
Wei Zhang

This paper completes a numerical research on steady momentum and heat transfer in power-law fluids in a channel. Weakly compressible laminar fluids are studied with no slip at the walls and uniform wall temperatures. The full governing equations are solved by continuous finite element method. Three thermal conductivity models are adopted in this paper, that is, constant thermal conductivity model, thermal conductivity varying as a function of temperature gradient, and a modified temperature-gradient-dependent thermal conductivity model. The results are compared with each other and the physical characteristics for values of parameters are also discussed in details. It is shown that the velocity curve from the solution becomes straight at higher power-law index. The effects of Reynolds numbers on the dilatant fluid and the pseudo-plastic look similar to each other and their trends can be easily predicted. Furthermore, for different models, the temperature curves also present pseudo-plastic and dilatant properties.

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Yanhai Lin ◽  
Liancun Zheng ◽  
Xinxin Zhang

This paper presents an investigation for magnetohydrodynamics (MHD) thermocapillary Marangoni convection heat transfer of an electrically conducting power-law fluid driven by temperature gradient. The surface tension is assumed to vary linearly with temperature and the effects of power-law viscosity on temperature fields are taken into account by modified Fourier law for power-law fluids (proposed by Pop). The governing partial differential equations are converted into ordinary differential equations and numerical solutions are presented. The effects of the Hartmann number, the power-law index and the Marangoni number on the velocity and temperature fields are discussed and analyzed in detail.


Author(s):  
Yan-Hong Ma ◽  
Hong-Wei Lu ◽  
Zheng-Dong Ma ◽  
Bin Zhu ◽  
Jie Hong

The heat transfer process of the Metal Rubber is in combination with the modes of heat transfer and the characteristics of Metal Rubber micro-element structure. Under certain conditions, the heat transfer questions can be simplified to the thermal conductivity questions. Based on the Fourier law, the characteristics of the thermal conductivity of Metal Rubber micro-element structure were analyzed by using thermoelectric analogy method. Combined with the equivalent coefficient law of the thermal conductivity, the thermal conductivity model was established. The formula of the thermal conductivity coefficient was derived. The accuracy of the theoretical model was verified by the experimental results. This study provides strong theoretical support for the application of the heat insulation materials.


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