Detailed film effectiveness measurements have been made on a cylindrical leading edge surface for steady and pulsating flows. The film hole is off centered by 21.5 deg from the centerline and angled 20 deg to the surface and 90 deg from the streamwise direction. Two jet-to-cross-flow velocity ratios have been considered: and 2, which correspond to blowing ratios of 1 and 2, respectively. The pulsating frequency is 10 Hz and the duty cycle is 50%. Comparisons between film effectiveness with a pulsating film and a continuous film show that for the same blowing ratio, the effectiveness of the film drops by a factor of 2 when the flow is pulsed. Hotwire measurements are made to characterize the pulsating velocity waveform at the exit of the film exit and verify the integrity of the pulse. The variation in the measured surface adiabatic wall temperature over the pulsing duration is very small, suggesting a large thermal inertia that keeps the wall surface largely unaffected by the time scale of the pulsations; this holds true for both blowing ratios tested.
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e-mail: lelgabry@aucegypt.edu
e-mail: richard.rivir@wpafb.af.mil
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July 2012
Research Papers
Effect of Pulsed Film Cooling on Leading Edge Film Effectiveness
Lamyaa A. El-Gabry,
Lamyaa A. El-Gabry
Department of Mechanical Engineering,
e-mail: lelgabry@aucegypt.edu
The American University in Cairo
, New Cairo 11835, Egypt
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Richard B. Rivir
Richard B. Rivir
Air Force Research Laboratory,
e-mail: richard.rivir@wpafb.af.mil
Propulsion Directorate
, Wright-Patterson AFB, OH 45433
Search for other works by this author on:
Lamyaa A. El-Gabry
Department of Mechanical Engineering,
The American University in Cairo
, New Cairo 11835, Egypte-mail: lelgabry@aucegypt.edu
Richard B. Rivir
Air Force Research Laboratory,
Propulsion Directorate
, Wright-Patterson AFB, OH 45433e-mail: richard.rivir@wpafb.af.mil
J. Turbomach. Jul 2012, 134(4): 041005 (6 pages)
Published Online: July 19, 2011
Article history
Received:
August 2, 2010
Revised:
August 10, 2010
Online:
July 19, 2011
Published:
July 19, 2011
Citation
El-Gabry, L. A., and Rivir, R. B. (July 19, 2011). "Effect of Pulsed Film Cooling on Leading Edge Film Effectiveness." ASME. J. Turbomach. July 2012; 134(4): 041005. https://doi.org/10.1115/1.4003653
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