This paper addresses the issue of aerodynamic consequences of small variations in airfoil profile. A numerical comparison of flow field and cascade pressure losses for two representative repaired profiles and a reference new vane were made. Coordinates for the three airfoil profiles were obtained from the nozzle guide vanes of refurbished turboshaft engines using 3D optical scanning and digital modeling. The repaired profiles showed differences in geometry in comparison with the new vane, particularly near the leading and trailing edges. A numerical simulation was conducted using a commercial CFD code, which uses the finite volume approach for solving the governing equations. The computational predictions of the aerodynamic performance were compared with experimental results obtained from a cascade consisting of blades with the same airfoil profiles. The CFD analysis was performed for the cascade at subsonic inlet and transonic exit conditions. Boundary layer growth, wake formation, and shock boundary layer interactions were observed in the two-dimensional computations. The flow field showed the presence of shock waves downstream of the passage throat and near the trailing edges of the blades. A conspicuous change in flow pattern due to subtle variation in airfoil profile was observed. The calculated flow field was compared with the flow pattern visualized in the experimental test rig using the schlieren method. The total pressure calculation for the cascade exit showed an increase in pressure loss for one of the off-design profiles. The pressure loss calculations were also compared with the multihole total pressure probe measurement in the transonic cascade rig.

1.
Woodason
,
R.
, 2009, “
An Experimental Investigation of the Influence of Service Exposure on the Aerodynamic Performance of Transonic Turbine Vanes
,” MS thesis, Royal Military College, Kingston, ON.
2.
Woodason
,
R.
,
Asghar
,
A.
, and
Allan
,
W. D. E.
, 2009, “
Assessment of Flow Quality of a Transonic Turbine Cascade
,” ASME Paper No. GT2009-60164.
3.
Cohen
,
H.
,
Rogers
,
G. F. C.
, and
Saravanamutto
,
H. I. H.
, 1996,
Gas Turbine Theory
,
4th ed.
,
Longman Group Ltd.
,
London, UK
.
4.
Wilson
,
D. G.
, 1984,
The Design of High-Efficiency Turbo-Machinery and Gas Turbines
,
MIT Press
,
Cambridge, MA
.
5.
Farokhi
,
S.
, 2009,
Aircraft Propulsion
,
Wiley
,
Hoboken, NJ
.
6.
Aungier
,
R. H.
, 2006,
Turbine Aerodynamics: Axial-Flow and Radial-Inflow Turbine Design and Analysis
,
ASME
,
New York
.
7.
Corriveau
,
D.
, and
Sjolander
,
S. A.
, 2004, “
Influence of Loading Distribution on the Performance of Transonic High Pressure Turbine Blades
,”
ASME J. Turbomach.
0889-504X,
126
(
2
), pp.
288
296
.
8.
Li
,
S. -M.
,
Chu
,
T. -L.
,
Yoo
,
Y. -S.
, and
Ng
,
W. F.
, 2004, “
Transonic and Low Supersonic Flow Losses of Two Steam Turbine Blades at Large Incidences
,”
ASME J. Turbomach.
0889-504X,
126
(
4
), pp.
966
975
.
9.
Sonoda
,
T.
,
Arima
,
T.
,
Olhofer
,
M.
,
Sendhoff
,
B.
,
Kost
,
F.
, and
Giess
,
P. -A.
, 2006, “
A Study of Advanced High-Loaded Transonic Turbine Airfoils
,”
ASME J. Turbomach.
0889-504X,
128
(
4
), pp.
650
657
.
10.
Forster
,
V. T.
, 1964, “
Turbine-Blading Development Using a Transonic Variable-Density Cascade Wind Tunnel
,”
Proc. Inst. Mech. Eng.
0020-3483,
179
(
6
), pp.
155
195
.
11.
Yasa
,
T.
,
Paniagua
,
G.
, and
Bussolin
,
A.
, 2007, “
Performance Analysis of a Transonic High-Pressure Turbine
,”
Proc. Inst. Mech. Eng., Part A
0957-6509,
221
, pp.
769
778
.
12.
Denton
,
J. D.
, and
Xu
,
L.
, 1990, “
The Trailing Edge Loss of Transonic Turbine Blades
,”
ASME J. Turbomach.
0889-504X,
112
(
2
), pp.
277
285
.
13.
Gostelow
,
J. P.
,
Mahallati
,
A.
,
Andrews
,
S. A.
, and
Carscallen
,
W. E.
, 2009, “
Measurement and Computation of Flowfield in Transonic Turbine Nozzle Blading With Blunt Trailing Edges
,” ASME Paper No. GT2009-59686.
14.
Mei
,
Y.
, and
Guha
,
A.
, 2005, “
Implicit Numerical Simulation of Transonic Flow Through Turbine Cascades on Unstructured Grids
,”
Proc. Inst. Mech. Eng., Part A
0957-6509,
219
, pp.
35
47
.
16.
Menter
,
F. R.
, 1994, “
Two-Equation Eddy Viscosity Turbulence Models for Engineering Applications
,”
AIAA J.
0001-1452,
32
(
8
), pp.
1598
1605
.
17.
Wilcox
,
D. C.
, 1988, “
Reassessment of Scale-Determining Equation for Advanced Turbulence Models
,”
AIAA J.
0001-1452,
26
(
11
), pp.
1299
1310
.
18.
Jones
,
W. P.
, and
Launder
,
R. E.
, 1972, “
The Prediction of Laminarization With a Two Equation Model of Turbulence
,”
Int. J. Heat Mass Transfer
0017-9310,
15
, pp.
301
314
.
19.
Garg
,
V. K.
, and
Ameri
,
A. A.
, 2001, “
Two-Equation Turbulence Models for Prediction of Heat Transfer on a Transonic Turbine Blade
,”
Int. J. Heat Fluid Flow
0142-727X,
22
, pp.
593
602
.
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