The boundary layer on the endwall of an axial turbomachine passage is influenced by streamwise and cross-stream pressure gradients, as well as a large streamwise vortex, that develop in the passage. These influences distort the structure of the boundary layer and result in heat transfer and friction coefficients that differ significantly from simple two-dimensional boundary layers. Three-dimensional contouring of the endwall has been shown to reduce the strength of the large passage vortex and reduce endwall heat transfer, but the mechanisms of the reductions on the structure of the endwall boundary layer are not well understood. This study describes three-component measurements of mean and fluctuating velocities in the passage of a turbine blade obtained with a laser Doppler velocimeter (LDV). Friction coefficients obtained with the oil film interferometry (OFI) method were compared to measured heat transfer coefficients. In the passage, the strength of the large passage vortex was reduced with contouring. Regions where heat transfer was increased by endwall contouring corresponded to elevated turbulence levels compared to the flat endwall, but the variation in boundary layer skew across the passage was reduced with contouring.

References

References
1.
Langston
,
L. S.
,
Nice
,
M. L.
, and
Hooper
,
R. M.
,
1977
, “
Three-Dimensional Flow Within a Turbine Cascade Passage
,”
ASME J. Eng. Power
,
99
(
1
), pp.
21
28
.
2.
Sharma
,
O. P.
, and
Butler
,
T. L.
,
1987
, “
Predictions of Endwall Losses and Secondary Flows in Axial Flow Turbine Cascades
,”
ASME J. Turbomach.
,
109
(
2
), pp.
229
236
.
3.
Sieverding
,
C. H.
,
1985
, “
Recent Progress in the Understanding of Basic Aspects of Secondary Flows in Turbine Blade Passages
,”
ASME J. Eng. Gas Turbines Power
,
107
(
2
), pp.
248
257
.
4.
Anderson
,
S. D.
, and
Eaton
,
J. K.
,
1989
, “
Reynolds Stress Development in Pressure-Driven Three-Dimensional Turbulent Boundary Layers
,”
J. Fluid Mech.
,
202
, pp.
263
294
.
5.
Johnston
,
J. P.
, and
Flack
,
K. A.
,
1996
, “
Review—Advances in Three-Dimensional Turbulent Boundary Layers With Emphasis on the Wall-Layer Regions
,”
ASME J. Fluids Eng.
,
118
(
2
), pp.
219
232
.
6.
Lewis
,
D. J.
, and
Simpson
,
R. L.
,
1998
, “
Turbulence Structure of Heat Transfer Through a Three-Dimensional Turbulent Boundary Layer
,”
J. Thermophys. Heat Transfer
,
12
(
2
), pp.
248
255
.
7.
Shizawa
,
T.
, and
Eaton
,
J. K.
,
1992
, “
Turbulence Measurements for a Longitudinal Vortex Interacting With a Three-Dimensional Turbulent Boundary Layer
,”
AIAA J.
,
30
(
1
), pp.
49
55
.
8.
Harrison
,
S.
,
1990
, “
Secondary Loss Generation in a Linear Cascade of High-Turning Turbine Blades
,”
ASME J. Turbomach.
,
112
(
4
), pp.
618
624
.
9.
Vera
,
M.
,
Blanco
,
E. D. L. R.
,
Hodson
,
H.
, and
Vazquez
,
R.
,
2009
, “
Endwall Boundary Layer Development in an Engine Representative Four-Stage Low Pressure Turbine Rig
,”
ASME J. Turbomach.
,
131
(
1
), p.
011017
.
10.
Harvey
,
N. W.
,
Rose
,
M. G.
,
Taylor
,
M. D.
,
Shahpar
,
S.
,
Hartland
,
J.
, and
Gregory-Smith
,
D. G.
,
2000
, “
Nonaxisymmetric Turbine End Wall Design: Part I—Three-Dimensional Linear Design System
,”
ASME J. Turbomach.
,
122
(
2
), pp.
278
285
.
11.
Hartland
,
J. C.
,
Gregory-Smith
,
D. G.
,
Harvey
,
N. W.
, and
Rose
,
M. G.
,
2000
, “
Nonaxisymmetric Turbine End Wall Design: Part II—Experimental Validation
,”
ASME J. Turbomach.
,
122
(
2
), pp.
286
293
.
12.
Germain
,
T.
,
Nagel
,
M.
,
Raab
,
I.
,
Schupbach
,
P.
,
Abhari
,
R. S.
, and
Rose
,
M.
,
2010
, “
Improving Efficiency of a High Work Turbine Using Nonaxisymmetric Endwalls—Part I: Endwall Design and Performance
,”
ASME J. Turbomach.
,
132
(
2
), p.
021007
.
13.
Schuepbach
,
P.
,
Abhari
,
R. S.
,
Rose
,
M. G.
,
Germain
,
T.
,
Raab
,
I.
, and
Gier
,
J.
,
2010
, “
Improving Efficiency of a High Work Turbine Using Nonaxisymmetric Endwalls—Part II: Time-Resolved Flow Physics
,”
ASME J. Turbomach.
,
132
(
2
), p.
021008
.
14.
Praisner
,
T. J.
,
Allen-Bradley
,
E.
,
Grover
,
E. A.
,
Knezevici
,
D. C.
, and
Sjolander
,
S. A.
,
2007
, “
Application of Non-Axisymmetric Endwall Contouring to Conventional and High-Lift Turbine Airfoils
,”
ASME
Paper No. GT2007-27579.
15.
Knezevici
,
D. C.
,
Sjolander
,
S. A.
,
Praisner
,
T. J.
,
Allen-Bradley
,
E.
, and
Grover
,
E. A.
,
2010
, “
Measurements of Secondary Losses in a Turbine Cascade With the Implementation of Nonaxisymmetric Endwall Contouring
,”
ASME J. Turbomach.
,
132
(
1
), p.
011013
.
16.
Saha
,
A. K.
, and
Acharya
,
S.
,
2008
, “
Computations of Turbulent Flow and Heat Transfer Through a Three-Dimensional Nonaxisymmetric Blade Passage
,”
ASME J. Turbomach.
,
130
(
3
), p.
031008
.
17.
Panchal
,
K. V.
,
Abraham
,
S.
,
Ekkad
,
S.
,
Ng
,
W. F.
,
Lohaus
,
A. S.
, and
Crawford
,
M. E.
,
2012
, “
Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Part 2—Heat Transfer Performance
,”
ASME
Paper No. GT2012-68405.
18.
Lynch
,
S. P.
,
Sundaram
,
N.
,
Thole
,
K. A.
,
Kohli
,
A.
, and
Lehane
,
C.
,
2011
, “
Heat Transfer for a Turbine Blade With Nonaxisymmetric Endwall Contouring
,”
ASME J. Turbomach.
,
133
(
1
), p.
011019
.
19.
Lynch
,
S. P.
,
Thole
,
K. A.
,
Kohli
,
A.
, and
Lehane
,
C.
,
2011
, “
Computational Predictions of Heat Transfer and Film-Cooling for a Turbine Blade With Nonaxisymmetric Endwall Contouring
,”
ASME J. Turbomach.
,
133
(
4
), p.
041003
.
20.
Lynch
,
S. P.
,
2011
, “
The Effect of Endwall Contouring on Boundary Layer Development in a Turbine Blade Passage
,” Ph.D. thesis, Virginia Tech, Blacksburg, VA.
21.
Moffat
,
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Therm. Fluid Sci.
,
1
(
1
), pp.
3
17
.
22.
Naughton
,
J. W.
, and
Sheplak
,
M.
,
2002
, “
Modern Developments in Shear-Stress Measurement
,”
Prog. Aerosp. Sci.
,
38
(
6–7
), pp.
515
570
.
23.
Holley
,
B. M.
,
Becz
,
S.
, and
Langston
,
L. S.
,
2006
, “
Measurement and Calculation of Turbine Cascade Endwall Pressure and Shear Stress
,”
ASME J. Turbomach.
,
128
(
2
), pp.
232
239
.
24.
Holley
,
B. M.
, and
Langston
,
L. S.
,
2009
, “
Surface Shear Stress and Pressure Measurements in a Turbine Cascade
,”
ASME J. Turbomach.
,
131
(
3
), p.
031014
.
25.
Lynch
,
S. P.
, and
Thole
,
K. A.
,
2008
, “
The Effect of Combustor-Turbine Interface Gap Leakage on the Endwall Heat Transfer for a Nozzle Guide Vane
,”
ASME J. Turbomach.
,
130
(
4
), p.
041019
.
26.
Kang
,
M. B.
, and
Thole
,
K. A.
,
2000
, “
Flowfield Measurements in the Endwall Region of a Stator Vane
,”
ASME J. Turbomach.
,
122
(
3
), pp.
458
466
.
You do not currently have access to this content.