Experimental Study on the Effect of Viscous Heating on the Temperature Field in Microchannel Gas Flow

Author(s):  
T. T. Zhang ◽  
L. Jia ◽  
C. W. Li ◽  
Y. Jaluria

An experimental system for single-phase gas flow in microchannels was set up. The effects of viscous heating on the temperature field in the flow were studied experimentally. Also, a theoretical model for the flow and heat transfer in the slip flow region was developed and the resulting equations were solved analytically by using a method based on the superposition principle. The results obtained agree well with the experimental data. The study also provides greater insight into microchannel flow and the associated heat transfer.

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
T. T. Zhang ◽  
L. Jia ◽  
C. W. Li ◽  
L. X. Yang ◽  
Y. Jaluria

An experimental system for single-phase gas flow in microtubes has been developed. The effects of viscous heating and compressibility on the flow and temperature field were studied for a wide range of governing parameters. Also, an analytical/numerical model of the flow was developed. Numerical results for the flow and heat transfer in the slip flow region were found to agree quite well with the experimental data, lending support to the model. The study provides greater physical insight into and understanding the effects of viscous dissipation and compressibility in microtube flow and the associated heat transfer. In addition, the combined experimental and numerical simulation approaches of the process can be used for control and optimization of systems based on microtube heat transfer.


Author(s):  
Tiantian Zhang ◽  
Li Jia ◽  
Zhicheng Wang ◽  
Yan Li ◽  
Xing Li

2-dimensional steady laminar fully-developed convective heat transfer between two parallel plates with constant heat flux boundary condition in slip flow region was solved analytically by using a new method based on superposition principle. Velocity slip, temperature jump at the wall and viscous heating effect were considered in the calculation. The solution method is verified for the cases where microscale effect is neglected (Kn = 0). Both the heating case and the cooling case were discussed. The effect of viscous heating on temperature and heat transfer was analyzed. The effect of Brinkman number and the Knudsen number on Nusselt number which express the heat transfer performance were analyzed systemically.


2011 ◽  
Vol 383-390 ◽  
pp. 6657-6662 ◽  
Author(s):  
Jun Xiao Feng ◽  
Qi Bo Cheng ◽  
Si Jing Yu

Based on the analysis of structural characteristic superiority, the process of combustion, flue gas flow and heat transfer in the upright magnesium reducing furnace, the three dimensional mathematical model is devoloped. And numerical simulation is performed further with the commercial software FLUENT. Finally, the flow and temperature field in furnace and temperature field in reducing pot have been obtained. The results indicate that the upright magnesium reducing furnace has perfect flue gas flow field and temperature field to meet the challenge of the magnesium reducing process; the major factors that affect the magnesium reducing reaction are the low thermal conductivity of slag and the high chemical reaction heat absorption.


2009 ◽  
Vol 85 (4) ◽  
pp. 40006 ◽  
Author(s):  
Tiantian Zhang ◽  
Li Jia ◽  
Zhicheng Wang ◽  
Chengwen Li ◽  
Yogesh Jaluria

Author(s):  
Tiantian Zhang ◽  
Li Jia ◽  
Jingru Zhang ◽  
Yogesh Jaluria

An experimental system on the fluid flow in microchannels with heat generation at the bottom has been set up. This system approximates the use of microchannel flow for the cooling of electronic components. The fabrication procedure of the test section is introduced briefly. Then, different flow rates and heat input have been proposed to study the effect of these parameters experimentally. Several numerical models have been given to simulate this process. By comparing the results from these models and the experimental data, it is found that the “two channel model”, which employ two channels with periodic boundary conditions, is the best model to simulate the overall heat transfer performance. The study considers the use of combined experimental and numerical simulation for an accurate and realistic modeling of such complex microchannel systems.


2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Zhenyu Liu ◽  
Zhiyu Mu ◽  
Huiying Wu

In this paper, a lattice Boltzmann (LB) model is established to simulate the gaseous fluid flow and heat transfer in the slip regime under the curved boundary condition. A novel curved boundary treatment is proposed for the LB modeling, which is a combination of the nonequilibrium extrapolation scheme for the curved boundary and the counter-extrapolation method for the macroscopic variables on the curved gas–solid interface. The established numerical model can accurately predict the velocity slip and temperature jump of the microscale gas flow on the curved surface, which agrees well with the analytical solution for the microcylindrical Couette flow and heat transfer. Then, the slip flow and the heat transfer over the single microcylinder are numerically studied in this work. It shows that the velocity slip and the temperature jump are obviously influenced by the Knudsen number and the Reynolds number, and the local Nusselt number depends on which gas rarefaction effect (velocity slip or temperature jump) is dominant. An increase in the Prandtl number leads to a decrease in the temperature jump, which enhances the heat transfer on the microcylinder surface. The numerical simulation of the flow and heat transfer over two microcylinders in tandem configuration are carried out to investigate the wake interference effect. The results show that the slip flow and heat transfer characteristics of the downstream microcylinder are influenced by the wake region behind the upstream cylinder as the spacing is small.


2018 ◽  
Vol 49 (2) ◽  
pp. 105-118
Author(s):  
Volf Ya. Borovoy ◽  
Vladimir Evguenyevich Mosharov ◽  
Vladimir Nikolaevich Radchenko ◽  
Arkadii Sergeyevich Skuratov

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