Cooling characteristics and entropy production of nanofluid flowing through tube

Alexandria Engineering Journal

Chu-Yun Cheng¹  Wei-Mon Yan²  Saman Rashidi³  Tien-Fu Yang⁴  C.J. Ho⁴ 

[1] Corresponding authors at Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (Wei-Mon Yan).;Research Center of Energy Conservation for New Generation of Residential, Commercial, and Industrial Sectors, National Taipei University of Technology, Taipei 10608, Taiwan;Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei 10608, Taiwan;Department of Mechanical Engineering, National Cheng-Kung University, Tainan 70101, Taiwan;

关键词: Nanofluid;    Conjugate heat transfer;    Heat transfer effectiveness ratio, energy efficiency;   

DOI  :  

来源: DOAJ

【 摘 要 】

In this work, the cooling effectiveness and entropy production of aluminum oxide–water nanofluid flow and heat transfer in the circular tube with the wall conduction effects are explored. All values of heat transfer effectiveness ratios are more than unity in this study. For a constant value of nanoparticles concentration, both heat transfer effectiveness ratios increase as the input temperature of fluid is increased. Both heat transfer effectiveness ratios are increased as the concentration of nanoparticles increases. Predictions show that all values of dimensionless local entropy production ratio are less than unity in this study except in the areas near the entrance of the heating part. This means that the usage of nanofluid is beneficial for decreasing the irreversibility of the system. The dimensionless local entropy production ratio decreases when the input temperature of fluid increases. The maximum value of Biw = 5 × 10-4 was reported for the Biot number in this study, which is far less than 0.1. As a consequence, the tube wall can be regarded as a Lumped system, and it is a reasonable assumption to ignore the radial thermal resistance.

【 授权许可】

Unknown