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Mathematical Problems in Engineering
Volume 2014 (2014), Article ID 981376, 7 pages
http://dx.doi.org/10.1155/2014/981376
Research Article

Numerical Calculations on Flow and Heat Transfer in Smooth and Ribbed Two-Pass Square Channels under Rotational Effects

1School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China
2Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China
3School of Mechanical Engineering, Northwestern Polytechnical University, P.O. Box 552, Xi’an, Shaanxi 710072, China

Received 30 March 2014; Accepted 5 May 2014; Published 15 May 2014

Academic Editor: Haochun Zhang

Copyright © 2014 Zhongyang Shen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

U-shaped channel, which is also called two-pass channel, commonly exists in gas turbine internal coolant passages. Ribbed walls are frequently adopted in internal passage to enhance the heat transfer. Considering the rotational condition of gas turbine blade on operation, the effect of rotation is also investigated for the coolant channel which is close to real operation condition. Thus, the objective of this study is to discuss the effect of rotation on fluid flow and heat transfer performance of U-shaped channel with ribbed walls under high rotational numbers. Investigated Reynolds number is Re and the rotation numbers are and 0.6. In the results, the spatially heat transfer coefficient distributions are exhibited to discuss the effect of rotation and roughened walls. It is found that ribbed walls enhance the heat transfer rate significantly. Under the rotational condition, the in the first pass with outward flow is increased while that in the second pass is decreased. Finally, average ratio, friction ratio, and thermal performance are all presented to discuss the thermal characteristics.