Curtis, or velocity compounded, stages commonly don’t achieve the same accuracy of performance prediction expected of most other turbine stages. A review of Curtis stage design practices, field wear, and dirt patterns, in conjunction with performance testing and computational fluid dynamics (CFD) modeling, determined that the nozzle/rotor aerodynamic interaction is far more complex than typical design and performance calculations assume. Understanding this nozzle/rotor interaction is key to obtaining both improved performance, and a more accurate performance prediction. This paper discusses the nature of this interaction, and it’s implications to Curtis stage performance prediction.

1.
Horlock
,
J. H.
, 1966,
Axial Flow Turbines, Fluid Dynamics and Thermodynamics
,
Robert E. Krieger Pub. Co.
, Malabar, FL, Sec. 3.3.3, pp.
81
84
.
2.
Horlock
,
J. H.
, 1966,
Axial Flow Turbines, Fluid Dynamics and Thermodynamics
,
Robert E. Krieger Pub. Co.
, Malabar, FL, Sec. 7.3.2, pp.
201
208
.
3.
Stratford
,
B. S.
, and
Sansome
,
G. E.
, 1959, “
The Performance of Supersonic Turbine Nozzles
,” R & M No. 3273, Aeronautical Research Council.
4.
Stratford
,
B. S.
, and
Sansome
,
G. E.
, 1960, “
Theory and Tunnel Tests of Rotor Blades for Supersonic Turbines
,” R & M No. 3275, Aeronautical Research Council.
5.
Kurzrock
,
J. W.
, 1989, “
Experimental Investigation of Supersonic Turbine Performance
,” ASME Paper No. 89-GT-238.
6.
Cumpsty
,
N. A.
, 1989,
Compressor Aerodynamics
,
Robert E. Krieger Pub. Co.
, Malabar, FL, Secs. 5.2 and 5.3, pp.
198
209
.
7.
Wang
,
X.
, and
Chen
,
J. P.
, 2004, “
A Post-Processor to Render Turbomachinery Flow Using Phase-Lag Simulations
,” AIAA Paper No. 2004-0615.
8.
Dorney
,
D. J.
,
Griffin
,
L. W.
,
Huber
,
F.
, and
Sondak
,
D. L.
, 2002, “
Unsteady Flow in a Supersonic Turbine With Variable Specific Heats
,”
Journal of Propulsion
,
18
(
2
),
493
496
.
9.
Gorrell
,
S. E.
,
Car
,
D.
,
Puterbaugh
,
S. L.
,
Estevadeordal
,
J.
, and
Okiishi
,
T. H.
, 2005, “
Investigation of Wake-Shock Interactions in a Transonic Compressor With DPIV and Time-Accurate CFD
,” ASME Paper No. GT2005-69107.
10.
Bakhle
,
M. A.
,
Liu
,
J. S.
,
Panovsky
,
J.
,
Kieth
,
T. G.
, and
Mehmed
,
O.
, 2002, “
Calculation and Correlation of the Unsteady Flowfield in a High Pressure Turbine
,” NASA Paper No. NASA/TM-2002-211475.
11.
Rashid
,
S.
, 1997–2001, personal notes.
12.
Chima
,
R. V.
, 2003,
TCGRID 3-D Grid Generator for Turbomachinery: User’s Manual and Documentation
, Version 300.
13.
Chen
,
J. P.
, and
Whitfield
,
D. L.
, 1993, “
Navier-Stokes Calculations for the Unsteady Flowfield of Turbomachinery
,” AIAA Paper No. 93-0676.
14.
Chen
,
J. P.
,
Celestina
,
M.
, and
Adamczyk
,
J. J.
, 1994, “
A New Procedure for Simulating Unsteady Flows Through Turbomachinery Blade Passages
,” ASME Paper No. 94-GT-151.
15.
Zhu
,
J.
, and
Shih
,
T. H.
, 1997, “
CMOTT Turbulence Model for NPARC
,” NASA Paper No. NASA CR 204143.
16.
Salisbury
,
J. K.
, 1950,
Steam Turbines and Their Cycles
,
Robert E. Krieger Pub. Co.
, Malabar, FL, Chap. 6, pp.
177
179
.
17.
Church
,
E. F.
, 1950,
Steam Turbines
,
McGraw-Hill
, New York, Secs. 5.9 and 5.10, pp.
154
158
.
You do not currently have access to this content.