TY - JOUR
T1 - A comparison of cylindrical and fan-shaped film-cooling holes on a vane endwall at low and high freestream turbulence levels
AU - Colban, W.
AU - Thole, K. A.
AU - Haendler, M.
PY - 2008/7
Y1 - 2008/7
N2 - Fan-shaped film-cooling holes have been shown to provide superior cooling performance to cylindrical holes along flat plates and turbine airfoils over a large range of different conditions. Benefits of fan-shaped holes include less required cooling air for the same performance, increased part lifetime, and fewer required holes. The major drawback, however, is increased manufacturing cost and manufacturing difficulty, particularly for the vane platform region. To this point, there have only been extremely limited comparisons between cylindrical and shaped holes on a turbine endwall at either low or high freestream turbulence conditions. This study presents film-cooling effectiveness measurements on an endwall surface in a large-scale, low-speed, twopassage, linear vane cascade. Results showed that film-cooling effectiveness decreased with increasing blowing rate for the cylindrical holes, indicating jet liftoff. However the fan-shaped passage showed increased film-cooling effectiveness with increasing blowing ratio. Overall, fanshaped holes increased film-cooling effectiveness by an average of 75% over cylindrical holes for constant cooling flow.
AB - Fan-shaped film-cooling holes have been shown to provide superior cooling performance to cylindrical holes along flat plates and turbine airfoils over a large range of different conditions. Benefits of fan-shaped holes include less required cooling air for the same performance, increased part lifetime, and fewer required holes. The major drawback, however, is increased manufacturing cost and manufacturing difficulty, particularly for the vane platform region. To this point, there have only been extremely limited comparisons between cylindrical and shaped holes on a turbine endwall at either low or high freestream turbulence conditions. This study presents film-cooling effectiveness measurements on an endwall surface in a large-scale, low-speed, twopassage, linear vane cascade. Results showed that film-cooling effectiveness decreased with increasing blowing rate for the cylindrical holes, indicating jet liftoff. However the fan-shaped passage showed increased film-cooling effectiveness with increasing blowing ratio. Overall, fanshaped holes increased film-cooling effectiveness by an average of 75% over cylindrical holes for constant cooling flow.
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U2 - 10.1115/1.2720493
DO - 10.1115/1.2720493
M3 - Article
AN - SCOPUS:49049112310
SN - 0889-504X
VL - 130
JO - Journal of Turbomachinery
JF - Journal of Turbomachinery
IS - 3
M1 - 031007
ER -