Film cooling experiments were run at the high-speed cascade wind tunnel of the University of the Federal Armed Forces Munich. The investigations were carried out on a linear cascade of highly loaded turbine blades. The main targets of the tests were to assess the film cooling effectiveness and the heat transfer in zones with main flow separation. The previous cascade was designed to have a large zone with flow separation on the pressure side starting at the leading edge and reaching up to approximately half of the axial chord. This cascade was changed for a new design with a larger pitch to chord ratio in order to set the focus on flow separation on the suction side. This increased pitch forces a massive separation on the suction side due to strong shocks. The flow separation is controlled with aid of vortex generating jets in order to reduce the total pressure loss caused by it. Film cooling is provided on the suction side upstream of the vortex generating jets. The measurements comprise of blade loading, profile loss, adiabatic film cooling effectiveness, and heat transfer coefficient under two Mach numbers at a Reynolds number of 390,000. In a previous publication detailed results with homogeneous inflow where shown. Now, the focus is set on the effects of periodic unsteady wakes resulting from bars moving upstream of the cascade. These moving bars create a periodic unsteady inflow similar to the interaction between stator and rotor in the machine. It is shown how these wakes have significant influence on the heat transfer in the acceleration region of the suction side and affect the adiabatic film cooling effectiveness upstream of the shock.

References

References
1.
Bunker
,
R. S.
,
2007
, “
Gas Turbine Heat Transfer: Ten Remaining Hot Gas Path Challenges
,”
ASME J. Turbomach.
,
129
, pp.
193
201
.10.1115/1.2464142
2.
Rigby
,
D. L.
, and
Heidmann
,
J. D.
,
2008
, “
Improved Film Cooling Effectiveness by Placing a Vortex Generator Downstream of Each Hole
,”
Proceedings of the ASME Turbo Expo 2008
, Berlin, June 9–13,
ASME
Paper No. GT2008-51361.10.1115/GT2008-51361
3.
Kusterer
,
K.
,
Elyas
,
A.
,
Bohn
,
D.
,
Sugimoto
,
T.
, and
Tanaka
,
R.
,
2008
, “
Double-Jet Film-Cooling for Highly Efficient Film-Cooling With Low Blowing Ratios
,”
Proceedings of the ASME Turbo Expo 2008
, Berlin, June 9–13,
ASME
Paper No. GT2008-50073.10.1115/GT2008-50073
4.
Lu
,
Y.
,
Dhungel
,
A.
,
Ekkad
,
S. V.
, and
Bunker
,
R. S.
,
2007
, “
Film Cooling Measurements for Cratered Cylindrical Inclined Holes
,”
Proceedings of the ASME Turbo Expo 2007
, Montreal, Canada, May 14–17,
ASME
Paper No. GT2007-27386.10.1115/GT2007-27386
5.
Haselbach
,
F.
, and
Schiffer
,
H.
,
2004
, “
Aerothermal Investigations on Turbine Endwalls and Blades
,”
Proceedings of the ASME Turbo Expo 2004
, Vienna, June 14–17,
ASME
Paper No. GT2004-53078.10.1115/GT2004-53078
6.
Janke
,
E.
, and
Wolf
,
T.
,
2010
, “
Aerothermal Research for Turbine Components—An Overview of the European AITEB-2 Project
,”
Proceedings of the ASME Turbo Expo 2010
, Glasgow, UK, June 14–18,
ASME
Paper No. GT2010-23511.10.1115/GT2010-23511
7.
Homeier
,
L.
,
Lutum
,
E.
,
Janke
,
E.
, and
Haselbach
,
F.
,
2004
, “
Aero-Thermodynamic Aspects of Film Cooling in Regions of Separated Flow on the Pressure Side of a High-Lift HPT Blade
,”
Proceedings of the ASME Turbo Expo 2004
, Vienna, June 14–17,
ASME
Paper No. GT2004-54067.10.1115/GT2004-54067
8.
Homeier
,
L.
, and
Haselbach
,
F.
,
2005
, “
Impact of Suction Side Cooling on the Losses of a Highly Loaded High Pressure Turbine Blade
,”
Proceedings of the 6th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics (ETC 6)
, Lille, France, March 7–11, Paper No. 021 04/156.
9.
Gad-el-Hak
,
M.
,
2000
,
Flow Control—Passive, Active and Reactive Flow Management
,
1st ed.
,
Cambridge University Press
,
Cambridge
, UK.
10.
Volino
,
R. J.
,
Kartuzova
,
O.
, and
Ibrahim
,
M. B.
,
2009
, “
Experimental and Computational Investigations of Low-Pressure Turbine Separation Control Using Vortex Generator Jets
,”
Proceedings of ASME Turbo Expo 2009
, Orlando, FL, June 8–12,
ASME
Paper No. GT2009-59983.10.1115/GT2009-59983
11.
Szwaba
,
R.
, and
Doerffer
,
P.
,
2011
, “
Separation Control by Air-Jet Vortex Generators on Turbine Blades
,”
Proceedings of the 9th European Turbomachinery Conference
, Istanbul, Turkey, March 21–25.
12.
Gomes
,
R. A.
, and
Niehuis
,
R.
,
2012
, “
Aerothermodynamics of a High-Pressure Blade With Very High Loading and Vortex Generators
,”
ASME J. Turbomach.
,
134
, p.
011020
.10.1115/1.4003052
13.
Pacciani
,
R.
,
Rubechini
,
F.
,
Arnone
,
A.
, and
Lutum
,
E.
,
2010
, “
Calculation of Steady and Periodic Unsteady Blade Surface Heat Transfer in Separated Transitional Flow
,”
Proceedings of the ASME Turbo Expo 2010
, Glasgow, UK, June 14–18,
ASME
Paper No. GT2010-23275.10.1115/GT2010-23275
14.
Flaszyński
,
P.
, and
Doerffer
,
P.
,
2011
, “
Numerical Simulations for Gas Turbine Cascade With Jet Vortex Generators
,”
Proceedings of the XX ISABE
, Gothenburg, Sweden, September 12–16, Paper No. ISABE-2011-1728.
15.
Sturm
,
W.
, and
Fottner
,
L.
,
1985
, “
The High-Speed Cascade Wind-Tunnel of the German Armed Forces University Munich
,”
8th Symposium on Measuring Techniques for Transonic and Supersonic Flows in Cascades and Turbomachines
, Genova, Switzerland, October 24–25.
16.
Acton
,
P.
, and
Fottner
,
L.
,
1996
, “
The Generation of Instationary Flow Conditions in the High-Speed Cascade Wind Tunnel of the German Armed Forces University Munich
,”
13th Symposium on Measuring Techniques
for Transonic and Supersonic Flow in Cascades and Turbomachines, Zurich, Switzerland, September 5–6.
17.
Doerffer
,
P.
,
Flaszyński
,
P.
, and
Szwaba
,
R.
,
2009
, “
New Concept of Test Section for Flow Modeling on Suction Side of Gas Turbine Blade
,”
Proceedings of the 19th ISABE Conference
, Montreal, Canada, September 7–11, Paper No. ISABE-2009-1324.
18.
Gomes
,
R.
, and
Niehuis
,
R.
,
2009
, “
Film Cooling Effectiveness Measurements on Highly Loaded Blades With Flow Separation
,”
Proceedings of the 8th European Conference on Turbomachinery, Fluid Dynamics and Thermodynamics (ETC 10)
, Graz, Austria, March 23–27, Paper No. 237.
19.
Gomes
,
R. A.
, and
Niehuis
,
R.
,
2011
, “
Film Cooling Effectiveness Measurements With Periodic Unsteady Inflow on Highly Loaded Blades With Main Flow Separation
,”
ASME J. Turbomach.
,
133
, p.
021019
.10.1115/1.4000568
20.
Woff
,
S.
,
Fottner
,
L.
, and
Ardey
,
S.
,
2002
, “
An Experimental Investigation of the Influence of Periodic Unsteady Inflow Conditions on Leading Edge Film Cooling
,”
Proceedings of the ASME Turbo Expo 2002
, Amsterdam, June 3–6,
ASME
Paper No. GT-2002-30202.10.1115/GT2002-30202
21.
Roach
,
P.
,
1986
, “
The Generation of Nearly Isotropic Turbulence by Means of Grids
,”
J. Heat Fluid Flow
,
8
, pp.
82
92
.10.1016/0142-727X(87)90001-4
22.
Gomes
,
R. A.
,
2010
, “
On Aerothermal Effects of Film Cooling on Turbine Blades With Flow Separation
,” Ph.D. thesis, Universität der Bundeswehr München, Neubiberg, Germany.
23.
Ammari
,
H.
,
Hay
,
N.
, and
Lampard
,
D.
,
1990
, “
Effect of Acceleration on the Heat Transfer Coefficient on a Film Cooled Surface
,”
Proceedings of the Gas Turbine and Aeroengine Congress and Exposition
, Brussels, Belgium, June 11–14, ASME Paper No. 90-GT-8.
24.
Ito
,
S.
,
Goldstein
,
R.
, and
Eckert
,
E.
,
1978
, “
Film Cooling of a Gas Turbine Blade
,”
ASME J. Eng. Power
,
100
, pp.
476
481
.10.1115/1.3446382
25.
Womack
,
K.
,
Volino
,
R.
, and
Schultz
,
M.
,
2007
, “
Measurements in Film Cooling Flows With Periodic Wakes
,”
Proceedings of the ASME Turbo Expo 2007
, Montreal, Canada, May 14–17,
ASME
Paper No. GT2007-27917.10.1115/GT2007-27917
26.
Wolff
,
S.
,
2003
, “
Aerodynamische Effekte bei Vorderkanten-Filmkühlausblasung an hochbelasteten Turbinengittern unter dem Einfluss periodisch instationärer Zuströmung
,” Ph.D. thesis, Universität der Bundeswehr München, Neubiberg, Germany.
27.
Gomes
,
R. A.
, and
Niehuis
,
R.
,
2011
, “
Film Cooling on Highly Loaded Blades With Main Flow Separation—Part 2: Overall Film Cooling Effectiveness
,”
Proceedings of the ASME Turbo Expo 2011
, Vancouver, Canada, June 6–10,
ASME
Paper No. GT2011-45477.10.1115/GT2011-45477
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