Library Subscription: Guest
Begell Digital Portal Begell Digital Library eBooks Journals References & Proceedings Research Collections
Journal of Enhanced Heat Transfer
IF: 0.562 5-Year IF: 0.605 SJR: 0.175 SNIP: 0.361 CiteScore™: 0.33

ISSN Print: 1065-5131
ISSN Online: 1026-5511

Journal of Enhanced Heat Transfer

DOI: 10.1615/JEnhHeatTransf.v18.i2.60
pages 149-165

CONJUGATED ANALYSIS OF HEAT TRANSFER ENHANCEMENT OF AN INTERNAL BLADE TIP-WALL WITH PIN-FIN ARRAYS

Gongnan Xie
Department of Mechanical and Power Engineering, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, China
Bengt Sunden
Division of Heat Transfer, Department of Energy Sciences, Lund University, P.O. Box 118, SE-22100, Lund, Sweden

ABSTRACT

To improve gas turbine performance, the operating temperature has been increased continuously. However, the heat transferred to the turbine blade is substantially increased as the turbine inlet temperature is increased. Cooling methods are, therefore, much needed for the turbine blades to ensure long durability and safe operation. The blade tip region is exposed to hot gas flow, and is difficult to cool. A common way to cool the tip is to use serpentine passages with 180-degree turns under the blade tip-cap, taking advantage of the three-dimensional (3D) turning effect and impingement. Increased internal convective cooling is, however, required to increase the blade tip life. In this paper, augmented heat transfer of a blade tip with internal pin fins has been investigated numerically using a conjugated heat transfer approach. The computational models consist of two-pass channels with 180-degree turns and pin-fin arrays mounted on the internal tip caps. The computational domain includes the fluid region and the solid pins as well as the solid tip regions. Turbulent convective heat transfer between the fluid and pins, and heat conduction within the pins and tip are simultaneously computed. The inlet Reynolds number ranges from 100,000 to 600,000. Details of the 3D fluid flow and heat transfer over the tip-walls are presented. A comparison of the overall performance of the models is presented. It was found that due to the combination of turning impingement and pin-fin crossflow, the heat transfer coefficient of the pin-finned tip is about three times higher than that of a smooth tip. This augmentation is achieved at the cost of a pressure drop penalty of 7%. With the conjugated heat transfer method, not only the simulated model is close to the experimental model, but also the distribution of the external tip heat transfer and pin-fin surface heat flux can be used in the thermal design of blade tips.


Articles with similar content:

Augmented Heat Transfer of an Internal Blade Tip by Full or Partial Arrays of Pin-Fins
Heat Transfer Research, Vol.42, 2011, issue 1
Bengt Sunden, Lieke Wang, Esa Utriainen, Gongnan Xie
AGUMENTED HEAT TRANSFER OF AN INTERNAL BLADE TIP BY FULL OR PARTIAL ARRAYS OF PIN-FINS
ICHMT DIGITAL LIBRARY ONLINE, Vol.0, 2009, issue
Bengt Sunden, Lieke Wang, Esa Utriainen, Gongnan Xie
Pressure loss and wall heat transfer characteristics in blade trailing-edge cooling passage
ICHMT DIGITAL LIBRARY ONLINE, Vol.0, 2012, issue
Yufeng Yao, M. Effendy, Jun Yao
Application of an Aerothermal Model for Effusion Cooling Systems and Finite Rate Chemistry in Aero-Engine Combustors
ICHMT DIGITAL LIBRARY ONLINE, Vol.0, 2015, issue
T. Aumeier, Thomas Behrendt
COMPUTATIONAL INVESTIGATION OF DIMPLE EFFECTS ON HEAT TRANSFER AND FRICTION FACTOR IN A LAMILLOY COOLING STRUCTURE
Journal of Enhanced Heat Transfer, Vol.22, 2015, issue 2
Lei Wang, Bengt Sunden, Lei Luo, Songtao Wang, Chenglong Wang