This paper reports on insights into the detailed thermodynamics of axial turbine nozzle guide vane (NGV) wakes as they interact with the rotor blades. The evidence presented is both computational and experimental. Unsteady Reynolds-averaged Navier–Stokes (RANS) simulations are used to compare the experimental observations with theoretical predictions. Output processing with both Eulerian and Lagrangian approaches is used to track the property variation of the fluid particles. The wake is found to be hot and loses heat to the surrounding fluid. The Lagrangian output processing shows that the entropy of the wake will fall due to heat loss as it passes through the rotor and this is corroborated experimentally. The experimental vehicle is a 1.5-stage shroudless turbine with modest Mach numbers of 0.5 and high response instrumentation. The entropy reduction of the wake is determined to be about four times the average entropy rise of the whole flow across the rotor. The results show that the work done by the wake fluid on the rotor is approximately 24% lower than that of the free-stream. The apparent experimental efficiency of the wake fluid is 114% but the overall efficiency of the turbine at midheight is around 95%. It is concluded that intrafluid heat transfer has a strong impact on the loss distribution even in a nominally adiabatic turbine with moderate row exit Mach numbers of 0.5.

References

1.
Dean
,
1959
, “
On the Necessity of Unsteady Flow in Fluid Machines
,”
ASME J. Basic Eng.
,
81
, pp.
24
28
.
2.
Smith
,
L. H.
,
1966
, “
Wake Dispersion in Turbomachines
,”
ASME J. Basic Eng.
,
88D
, pp.
688
690
.10.1115/1.3645942
3.
Rose
,
M. G.
, and
Harvey
,
N. W.
,
2000
, “
Turbomachinery Wakes: Differential Work and Mixing Loss
,”
ASME J. Turbomach.
,
122
, pp.
68
77
.10.1115/1.555429
4.
Hodson
,
H. P.
, and
Dawes
,
W. N.
,
1998
, “
On the Interpretation of Measured Profile Losses in Unsteady Wake-Turbine Blade Interaction Studies
,”
ASME J. Turbomach.
,
120
, pp
276
284
.10.1115/1.2841403
5.
Hodson
,
H. P.
,
1985
, “
An Inviscid Blade-to-Blade Prediction of a Wake Generated Unsteady Flow
,”
ASME J. Eng. Gas Turbines Power
,
107
, pp.
467
476
.10.1115/1.3239751
6.
Denton
,
J. D.
,
1993
, “
Loss Mechanisms in Turbomachines
,”
ASME J. Turbomach.
,
115
, p.
621
. 10.1115/1.2929299
7.
Praisner
,
T. J.
,
Clark
,
J. P.
,
Nash
,
T. C.
,
Rice
,
M. J.
, and
Grover
,
E. A.
,
2006
, “
Performance Impacts Due to Wake Mixing in Axial Flow Turbomachinery
,”
ASME Turbo Expo 2006
,
Barcelona, Spain
, May 8–11,
ASME
Paper No. GT2006-90666.10.1115/GT2006-90666
8.
Thorpe
,
S. J.
,
Miller
,
R. J.
,
Yoshino
,
S.
,
Ainsworth
,
R. W.
, and
Harvey
,
N. W.
,
2005
, “
The Effect of Work Processes on the Casing Heat Transfer of a Transonic Turbine
,”
ASME Turbo Expo 2005
, June 6–9,
ASME
Paper No. GT2005-68437.10.1115/GT2005-68437
9.
Mokulys
,
T.
,
Dewhurst
,
S. C.
, and
Abhari
,
R. S.
,
2005
Numerical Validation of Characteristic and Linearized Unsteady Boundary Conditions for Non-Integer Blade Ratios in a Non-Linear Navier Stokes Solver
,”
Proceedings of the IGTI Turbo Expo 2005
,
Reno, NV
,
June 6–9
,
ASME
Paper No. GT2005-68670.10.1115/GT2005-68670
10.
Mokulys
,
T.
,
Ferrari
,
F.
,
Haertel
,
C.
, and
Abhari
R. S
,
2003
, “
Uncertainty Analysis of Predicted Heat Transfer for Turbomachinery Flows
,”
Proceedings of the Conference of Modelling Fluid Flow, CMFF
,
Budapest
,
September 3–6
.
11.
Baldini
,
L.
, “
Turbine Unsteady Wake/Blade Row Interaction
,” Semester thesis WS 02/03,
LSM ETH Zürich
.
12.
Petters
,
C.
,
2006
, “
The Thermodynamics of Unsteady Wake-Blade Interaction
,” Studienarbeit, ITLR uni-Stuttgart.
13.
Kachel
,
C.
,
Denton
,
J. D.
,
2006
, “
Experimental and Numerical Investigation of the Unsteady Surface Pressure in a Three-Stage Model of an Axial High Pressure Turbine
,”
ASME J. Turbomach.
,
128
, p
261
.10.1115/1.1860378
14.
Sigg
,
R.
,
2004
, “
Particle Paths
,” Final Report Oct’04 to Dec’04,
LSM ETH Zürich
.
15.
Sell
,
M.
,
Schlienger
,
J.
,
Pfau
,
A.
,
Treiber
,
M.
, and
Abhari
,
R. S.
,
2001
, “
The 2-Stage Axial Turbine Test Facility LISA
,”
ASME
Paper No. 2001-GT-0492.
16.
Behr
,
T.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2007
, “
Unsteady Flow Physics and Performance of a One-and-1/2-Stage Turbine
,”
ASME J. Turbomach.
,
129
(
2
), pp.
348
359
.10.1115/1.2447707
17.
Kupferschmied
,
P.
,
Kopperl
,
O.
,
Gizzi.
W. P.
, and
Gyarmathy
,
G.
,
2000
, “
Time-Resolved Flow Measurements With Fast Aerodynamic Probes in Turbomachinery
,”
Meas. Sci. Technol.
,
11
, pp.
1036
1054
.10.1088/0957-0233/11/7/318
18.
Pfau
,
A.
,
Schlienger
,
J.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2003
, “
Unsteady, 3-Dimensional Flow Measurement Using a Miniature Virtual 4 Sensor Fast Response Aerodynamic Probe (FRAP)
,”
ASME
Paper No. GT2003-38128.10.1115/GT2003-38128
19.
Mansour
,
M.
,
Chokani
,
N.
,
Kalfas
,
A.I.
, and
Abhari
,
R.S.
,
2008
, “
Time-Resolved Entropy Measurements Using a Fast Response Entropy Probe
,”
Meas. Sci. Technol.
,
19
, p.
115401
.10.1088/0957-0233/19/11/115401
20.
Mansour
,
M.
,
Chokani
,
N.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2008
, “
Unsteady Entropy Measurement in a High-Speed Radial Compressor
,”
ASME J. Eng. Gas Turbines Power
,
130
(
2
), p.
021603
.10.1115/1.2799525
21.
Mansour
,
M.
,
Chokani
,
N.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2008
, “
Impact of Time-Resolved Entropy Measurement on a One-and-1/2-Stage Turbine Performance
,”
ASME
Paper No. GT2008-50807.10.1115/GT2008-50807
22.
Schuepbach
,
P.
,
Rose
,
M. G.
,
Abhari
,
R. S.
,
Germain
,
T.
,
Raab
,
I.
, and
Gier
,
J.
,
2008
, “
Effects of Suction and Injection of Purge-Flow on the Secondary Flow Structures of a High-Work Turbine
,”
ASME
Paper No. GT2008-50471.10.1115/GT2008-50471
23.
Porreca
,
L.
,
Hollenstein
,
M.
,
Kalfas
,
A. I.
, and
Abhari
,
R. S.
,
2007
, “
Turbulence Measurement and Analysis in a Multistage Axial Turbine
,”
J. Propul. Power
,
23
(
1
), pp.
227
23
.10.2514/1.20022
You do not currently have access to this content.