@Article{AAMM-3-297,
author = {Xie , Gongnan and Sundén , Bengt},
title = {Comparisons of Heat Transfer Enhancement of an Internal Blade Tip with Metal or Insulating Pins},
journal = {Advances in Applied Mathematics and Mechanics},
year = {2011},
volume = {3},
number = {3},
pages = {297--309},
abstract = {<p style="text-align: justify;">Cooling methods are needed for turbine blade tips to ensure a long
durability and safe operation. A common way to cool a tip is to use
serpentine passages with 180-deg turn under the blade tip-cap taking
advantage of the three-dimensional turning effect and impingement like
flow. Improved internal convective cooling is therefore required to
increase the blade tip lifetime. In the present study, augmented heat
transfer of an internal blade tip with pin-fin arrays has been investigated
numerically using a conjugate heat transfer method. The computational domain
includes the fluid region and the solid pins as well as the tip regions.
Turbulent convective heat transfer between the fluid and pins, and heat
conduction within pins and tip are simultaneously computed. The main
objective of the present study is to observe the effect of the pin
material on heat transfer enhancement of the pin-finned tips. It is
found that due to the combination of turning, impingement and pin-fin
crossflow, the heat transfer coefficient of a pin-finned tip is a factor
of 2.9 higher than that of a smooth tip at the cost of an increased pressure
drop by less than 10%. The usage of metal pins can reduce the tip temperature
effectively and thereby remove the heat load from the tip. Also, it is found
that the tip heat transfer is enhanced even by using insulating pins having
low thermal conductivity at low Reynolds numbers. The comparisons of overall
performances are also included.</p>},
issn = {2075-1354},
doi = {https://doi.org/10.4208/aamm.10-10s2-03},
url = {http://global-sci.org/intro/article_detail/aamm/170.html}
}