RST model for turbulent flow and heat transfer mechanism in an outward convex corrugated tube

2014 ◽  
Vol 91 ◽  
pp. 107-129 ◽  
Author(s):  
Huai-Zhi Han ◽  
Bing-Xi Li ◽  
Feng-Chen Li ◽  
Yu-Rong He
Author(s):  
Yigang Luan ◽  
Lianfeng Yang ◽  
Bo Wan ◽  
Tao Sun

Gas turbine engines have been widely used in modern industry especially in the aviation, marine and energy fields. The efficiency of gas turbines directly affects the economy and emissions. It’s acknowledged that the higher turbine inlet temperatures contribute to the overall gas turbine engine efficiency. Since the components are subject to the heat load, the internal cooling technology of turbine blades is of vital importance to ensure the safe and normal operation. This paper is focused on exploring the flow and heat transfer mechanism in matrix cooling channels. In order to analyze the internal flow field characteristics of this cooling configuration at a Reynolds number of 30000 accurately, large eddy simulation method is carried out. Methods of vortex identification and field synergy are employed to study its flow field. Cross-sectional views of velocity in three subchannels at different positions have been presented. The results show that the airflow is strongly disturbed by the bending part. It’s concluded that due to the bending structure, the airflow becomes complex and disordered. When the airflow goes from the inlet to the turning, some small-sized and discontinuous vortices are formed. Behind the bending structure, the size of the vortices becomes big and the vortices fill the subchannels. Because of the structure of latticework, the airflow is affected by each other. Airflow in one subchannel can exert a shear force on another airflow in the opposite subchannel. It’s the force whose direction is the same as the vortex that enhances the longitudinal vortices. And the longitudinal vortices contribute to the energy exchange of the internal airflow and the heat transfer between airflow and walls. Besides, a comparison of the CFD results and the experimental data is made to prove that the numerical simulation methods are reasonable and acceptable.


2007 ◽  
Vol 2007.12 (0) ◽  
pp. 197-200
Author(s):  
Yuhki TAKAHASHI ◽  
Yasuo KOIZUMI ◽  
Hiroyasu OHTAKE ◽  
Tohru MIYASHITA ◽  
Michitsugu MORI

1983 ◽  
Vol 48 (6) ◽  
pp. 1695-1702
Author(s):  
František Vašák ◽  
Václav Kolář ◽  
Zdeněk Brož

An analysis is performed of available experimental data on heat transfer in the region of very low Prandtl numbers 0.005 ⪬ Pr ⪬ 3. None of the verified models on heat transfer mechanism agrees with experimental data in the whole studied region. With regard to a small number of experimental data it is not possible to make a final decision whether the disagreement is due to inacuracies in experiments or on the side of theory.


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