The objective of this work presented in this paper is to study the performance of low-pressure turbines in detail by extensive numerical simulations. The numerical flow simulations were conducted using the general purpose code ANSYS CFX. Particular attention is focused on the loss development in the axial direction within the flow passage of the cascade. It is shown that modern computational fluid dynamics (CFD) tools are able to break down the integral loss of the turbine profile into its components, depending on attached and separated flow areas. In addition, the numerical results allow one to show the composition of the loss depending on the Reynolds number. The method of the analysis of axial loss development presented here allows for a much more comprehensive investigation and evaluation of the quality of the numerical results. For this reason, the paper also demonstrates the capability of this method to quantify the influence of the axial velocity density ratio, the inflow turbulence level, the inflow angle, and the Reynolds number on the loss configuration and the flow angle of the cascade as well as a comparison of steady state and transient results. The validation data of this low pressure turbine (LPT) cascade have been obtained at the High Speed Cascade Wind Tunnel of the Institute of Jet Propulsion. For this purpose, experiments were conducted within the range of $Re2th$ = 40,000 to 400,000. To gather data at realistic engine operation conditions, the wind tunnel allows for an independent variation of Reynolds and Mach number. The experimental results presented herein contain detailed pressure measurements as well as measurements with 3D hot-wire anemometry. However, this paper shows only integral values of the experimental as well as the numerical results to protect the proprietary nature of the LPT design.

## References

References
1.
Steffens
,
K.
, and
Fritsch
,
G.
,
1999
, “
Enabling Low Spool Technologies for Future High-Bypass Ratio Engines
,” 14th International Symposium on Airbreathing Engines, Florence, Italy, September 5–10, Paper No. ISABE 99-721.
2.
Sturm
,
W.
, and
Fottner
,
L.
,
1985
, “
The High-Speed Cascade Wind Tunnel of the German Armed Forces Munich
,”
8th Symposium on Measuring Techniques for Transonic and Supersonic Flows in Cascades and Turbomachines
,
Genoa
, October 24–25.
3.
,
P.
,
Fottner
,
L.
, and
Fiala
,
A.
,
2000
, “
Experimental and Numerical Investigation of Wake-Induced Transition on a Highly Loaded LP Turbine at Low Reynolds Numbers
,” ASME Paper No. 2000-GT-0269.
4.
Menter
,
F. R.
,
Langtry
,
R. B.
,
Likki
,
S. R.
,
Suzen
,
Y. B.
,
Huang
,
P. G.
, and
Völker
,
S.
,
2004
, “
A Correlation-Based Transition Model Using Local Variables: Part I—Model Formulation
,” ASME Turbo Expo, Vienna, Austria, June 14–17,
ASME
Paper No. GT2004-53452.10.1115/GT2004-53452
5.
Langtry
,
R. B.
,
Menter
,
F. R.
,
Likki
,
S. R.
,
Suzen
,
Y. B.
,
Huang
,
P. G.
, and
Völker
,
S.
,
2004
, “
A Correlation-Based Transition Model Using Local Variables: Part II—Test Cases and Industrial Applications
,”
ASME Turbo Expo
, Vienna, Austria, June 14–17,
ASME
Paper No. GT2004-53454.10.1115/GT2004-53454
6.
Menter
,
R. R.
,
Kurtz
,
M.
, and
Langtry
,
R.
,
2003
, “
Ten Years of Industrial Experience With the SST Turbulence Model
,” Proc. 4th. Int. Symp. on Turbulence, Heat and Mass Transfer, Antalya, Turkey, October 12–17,
K.
Hanjalić
, ed.,
Begell House
,
New York
.
7.
Kožulović
,
D.
, and
Röber
,
T.
,
2006
, “
Contribution of Turbulence Equation Terms to the Shear Stress Balance
,” Proc. 4th ICCFD, Gent, The Netherlands.
8.
Langtry
,
R. B.
, and
Menter
,
F. R.
,
2005
, “
Transition Modelling for General CFD Applications in Aeronautics
,”
AIAA
Paper No. 2005-522.10.2514/6.2005-522
9.
Abu-Ghannam
,
B. J.
, and
Shaw
,
R.
,
1980
, “
Natural Transition of Boundary Layers—The Effects of Pressure Gradient and Flow History
,”
J. Mech. Eng. Sci.
,
22
(
5
), pp.
213
228
.10.1243/JMES_JOUR_1980_022_043_02
10.
Suzen
,
Z. B.
,
Xiong
,
G.
, and
Huang
,
P. G.
,
2000
, “
Predictions of Transitional Flows in Low-Pressure Turbines Using an Intermittency Transport Equation
,”
AIAA Fluids 2000 Conference
, Denver, CO, June 19–22,
AIAA
Paper No. 2000-2654.10.2514/6.2000-2654
11.
Mayle
,
R. E.
,
1991
, “
The Role of Laminar-Turbulent Transition in Gas Turbine Engines
,” ASME Turbo Expo, Orlando, FL, June 3–6,
ASME
Paper No. 91-GT-261.
12.
Muth
,
B.
,
Schwarze
,
M.
,
Niehuis
,
R.
, and
Franke
,
M.
,
2009
, “
Investigation of CFD Prediction Capabilities for Low Reynolds Turbine Aerodynamics
,” ASME Turbo Expo, Orlando, FL, June 8–12,
ASME
Paper No. GT2009-59306.10.1115/GT2009-59306
13.
Muth
,
B.
,
2012
, “
Einfluss kleiner Reynolds-Zahlen auf das Verlust- und Umlenkverhalten von Niederdruckturbinengittern
,”
Ph.D. thesis
,
University of the German Federal Armed Forces, Department of Aeronautics and Aerospace
,
Munich, Germany
.
14.
Martinstetter
,
M.
,
Schwarze
,
M.
,
Niehuis
,
R.
, and
Hübner
,
N.
,
2008
, “
Influence of Inflow Turbulence on Loss Behavior of Highly Loaded LPT Cascades
,” 46th AIAA Aerospace Sciences Meeting and Exhibit, Reno-Tahoe, NV, January 7–10,
AIAA
Paper No. 2008-82.10.2514/6.2008-82
15.
Kiock
,
R.
,
,
G.
, and
Hoheisel
,
H.
,
1982
, “
Die Erzeugung höherer Turbulenzgrade in der Meßstrecke des Hochgeschwindigkeits-Gitterwindkanals, Braunschweig, zur Simulation turbomaschinenähnlicher Bedingungen
,”
Institut für Entwurfsaerodynamik, DFVLR Braunschweig
, Paper No. FB-82-25.
16.
Banieghbal
,
M.
,
Curtis
,
E.
,
Denton
,
J.
,
Hodson
,
H.
,
Huntsman
,
I.
,
Schulte
,
V.
,
Harvey
,
N.
, and
Steele
,
A.
,
1995
, “
Wake Passing in LP Turbine Blades
,” 85th Symposium on Loss Mechanisms and Unsteady Flows in Turbomachines (AGARD CP-571), Derby, UK, May 8–12.
17.
Martinstetter
,
M.
,
2010
, “
Experimentelle Untersuchungen zur Aerodynamik hoch belasteter Niederdruckturbinen-Beschaufelungen
,”
Ph.D. Thesis
,
University of the German Federal Armed Forces, Department of Aeronautics and Aerospace
,
Munich, Germany
.
18.
Coull
,
J.
,
Thomas
,
R.
, and
Hodson
,
H.
,
2008
, “
Velocity Distributions for Low Pressure Turbines
,”
ASME
Paper No. GT2008-50589.10.1115/GT2008-50589
19.
Curtis
,
E.
,
Hodson
,
H.
,
Banieghbal
,
M.
,
Howell
,
R.
, and
Harvey
,
N.
,
1997
, “
Development of Blade Profiles for Low-Pressure Turbine Applications
,”
ASME J. Turbomach.
,
119
, pp.
531
538
.10.1115/1.2841154
20.
Sharma
,
O.
,
Wells
,
R.
,
,
R. H.
, and
Bailey
,
D.
,
1982
, “
Boundary Layer Development on Turbine Suction Surfaces
,”
ASME J. Eng. Power
,
104
, pp.
698
706
.10.1115/1.3227334
21.
Baines
,
W.
, and
Peterson
,
E.
,
1951
, “
An Investigation of Flow Through Screens
,”
Trans. ASME
,
73
, pp.
467
480
.
22.
,
M.
, and
Fottner
,
L.
,
1993
, “
Experimental Investigations of the Influence of Incoming Wakes on the Losses of a Linear Turbine Cascade
,” ASME Paper No. 93-GT-394.
23.
Schulte
,
V.
, and
Hodson
,
H.
,
1994
, “
Wake-Separation Bubble Interaction in Low Pressure Turbines
,”
AIAA/SAE/ASME/ASEE 30th Joint Propulsion Conference and Exhibit
, Indianapolis, IN, June 27–29,
AIAA
Paper No. 94-2931.10.2514/6.1994-2931
24.
Stieger
,
R.
, and
Hodson
,
H.
,
2003
, “
,” Proceedings of ASME Turbo Expo, Power for Land, Sea and Air, Atlanta, GA, June 16–19,
ASME
Paper No. GT2003-38304.10.1115/GT2003-38304
25.
Pfeil
,
H.
,
Herbst
,
R.
, and
Schröder
,
T.
,
1983
, “
Investigation of the Laminar-Turbulent Transition of Boundary Layers Disturbed by Wakes
,”
ASME J. Eng. Power
,
105
, pp.
130
137
.10.1115/1.3227373