The usual ways to measure the aerodynamic forcing function are complex and expensive. The aim of this work is to evaluate the forces acting on the blades using a relatively simpler experimental methodology based on a time-resolved pressure measurement at the rotor discharge. Upstream of the rotor, a steady three holes probe (3HP) has been used. The postprocessing procedures are described in detail, including the application of a phase-locked average and of an extension algorithm with phase-lag. The algorithm for the computation of the force components is presented, along with the underlying assumptions. In order to interpret the results, a preliminary description of the flowfield, both upstream and downstream of the rotor, is provided. This gives an insight of the most relevant features that affect the computation of the forces. Finally, the analysis of the results is presented. These are first described and then compared with overall section-average results (torque-sensor), and with the results from 3D unsteady simulations (integral of pressure over the blade surface) in order to assess the accuracy of the method. Both the experimental and the numerical results are also compared for two different operating conditions with increasing stage load.

References

References
1.
Mailach
,
R.
, and
Vogeler
,
K.
,
2004
, “
Aerodynamic Blade Row Interactions in an Axial Compressor—Part II: Unsteady Profile Pressure Distribution and Blade Forces
,”
ASME J. Turbomach.
,
126
(
1
), pp.
45
51
.
2.
Miller
,
R. J.
,
Moss
,
R. W.
,
Ainsworth
,
R. W.
, and
Harvey
,
N. W.
,
2003
, “
Wake, Shock, and Potential Field Interactions in a 1.5 Stage Turbine—Part I: Vane-Rotor and Rotor-Vane Interaction
,”
ASME. J. Turbomach.
,
125
(
1
), pp.
33
39
.
3.
Kammerer
,
A.
, and
Abhari
,
R. S.
,
2009
, “
Blade Forcing Function and Aerodynamic Work Measurements in a High Speed Centrifugal Compressor With Inlet Distortion
,”
ASME
Paper No. GT2009-59911.
4.
Kemp
,
N. H.
, and
Sears
,
W. R.
,
1953
, “
Aerodynamic Interference Between Moving Blade Rows
,”
J. Aeronaut. Sci.
,
20
(
9
), pp.
585
598
.
5.
Meyer
,
R. X.
,
1958
, “
The Effect of Wakes on the Transient Pressure and Velocity Distribution on Turbomachines
,”
ASME J. Basic Eng.
,
80
(
4
), pp.
1544
1552
.
6.
Lefcort
,
M. D.
,
1965
, “
An Investigation Into the Unsteady Blade Forces in Turbomachines
,”
ASME J. Eng. Power
,
87
(
4
), pp.
345
354
.
7.
Korakianitis
,
T. T.
,
1992
, “
On the Prediction of Unsteady Forces on Gas Turbine Blades: Part 1—Description of the Approach
,”
ASME J. Turbomach.
,
114
(
1
), pp.
114
122
.
8.
Moffatt
,
S.
,
Ning
,
W.
,
Li
,
Y.
,
Wells
,
R. G.
, and
He
,
L.
,
2005
, “
Blade Forced Response Prediction for Industrial Gas Turbines
,”
J. Propul. Power
,
21
(
4
), pp.
707
714
.
9.
Dring
,
R. P.
,
Joslyn
,
H. D.
,
Hardin
,
L. W.
, and
Wagner
,
J. H.
,
1982
, “
Turbine Rotor-Stator Interaction
,”
ASME J. Eng. Power
,
104
(
4
), pp.
729
742
.
10.
Miller
,
R. J.
,
Moss
,
R. W.
,
Ainsworth
,
R. W.
, and
Horwood
,
C. K.
,
2003
, “
Time-Resolved Vane-Rotor Interaction in a High-Pressure Turbine Stage
,”
ASME J. Turbomach.
,
125
(
1
), pp.
1
13
.
11.
Dénos
,
R.
,
Arts
,
T.
,
Paniagua
,
G.
,
Michelassi
,
V.
, and
Martelli
,
F.
,
2001
, “
Investigation of the Unsteady Rotor Aerodynamics in a Transonic Turbine Stage
,”
ASME J. Turbomach.
,
123
(
1
), pp.
81
89
.
12.
Arndt
,
N.
,
1993
, “
Blade Row Interaction in a Multistage Low-Pressure Turbine
,”
ASME J. Turbomach.
,
115
(
1
), pp.
137
146
.
13.
Paradiso
,
B.
,
Gaetani
,
P.
,
Mora
,
A.
,
Dossena
,
V.
,
Osnaghi
,
C.
,
Arcangeli
,
L.
,
Gerbi
,
F.
,
Maceli
,
N.
, and
Quadrelli
,
R.
,
2015
, “
Design and Operation of a Low Speed Test Turbine Facility
,”
European Turbomachinery Conference
, Paper No. ETC2015-223.
14.
Paradiso
,
B.
,
Mora
,
A.
,
Dossena
,
V.
,
Gatti
,
G.
,
Nesti
,
A.
,
Arcangeli
,
L.
, and
Maceli
,
N.
,
2015
, “
Flow Evolution in a One and a Half Axial Steam Turbine Stage Under Different Operating Conditions
,”
ASME
Paper No. GT2015-43201.
15.
Persico
,
G.
,
Gaetani
,
P.
, and
Guardone
,
A.
,
2005
, “
Design and Analysis of New Concept Fast-Response Pressure Probes
,”
J. Meas. Sci. Technol.
,
16
(
9
), pp.
1741
1750
.
16.
Gaetani
,
P.
,
Persico
,
G.
,
Dossena
,
V.
, and
Osnaghi
,
C.
,
2006
, “
Investigation of the Flow Field in a High-Pressure Turbine Stage for Two Stator-Rotor Axial Gaps—Part II: Unsteady Flow Field
,”
ASME J. Turbomach.
,
129
(
3
), pp.
580
590
.
17.
Schennach
,
O.
,
Woisetschläger
,
J.
,
Paradiso
,
B.
,
Persico
,
G.
, and
Gaetani
,
P.
,
2009
, “
Three Dimensional Clocking Effects in a One and a Half Stage Transonic Turbine
,”
ASME J. Turbomach.
,
132
(
1
), p.
011019
.
18.
Arnone
,
A.
,
1994
, “
Viscous Analysis of Three-Dimensional Rotor Flow Using a Multigrid Method
,”
ASME J. Turbomach.
,
116
(
3
), pp.
435
445
.
19.
Arnone
,
A.
,
Carnevale
,
E.
, and
Marconcini
,
M.
,
1997
, “
Grid Dependency Study for the NASA Rotor 37 Compressor Blade
,”
ASME
Paper No. 97-GT-384.
20.
Pacciani
,
R.
,
Rubechini
,
F.
,
Arnone
,
A.
, and
Lutum
,
E.
,
2012
, “
Calculation of Steady and Periodic Unsteady Blade Surface Heat Transfer in Separated Transitional Flow
,”
ASME J. Turbomach.
,
134
(
6
), p.
061037
.
21.
Marconcini
,
M.
,
Rubechini
,
F.
,
Arnone
,
A.
, and
Ibaraki
,
S.
,
2010
, “
Numerical Analysis of the Vaned Diffuser of a Transonic Centrifugal Compressor
,”
ASME J. Turbomach.
,
132
(
4
), p.
041012
.
22.
Rubechini
,
F.
,
Marconcini
,
M.
,
Arnone
,
A.
,
Scotti Del Greco
,
A.
, and
Biagi
,
R.
,
2013
, “
Special Challenges in the Computational Fluid Dynamics Modeling of Transonic Turbo-Expanders
,”
ASME J. Eng. Gas Turbines Power
,
135
(
10
), p.
102701
.
23.
Giovannini
,
M.
,
Marconcini
,
M.
,
Arnone
,
A.
, and
Bertini
,
F.
,
2014
, “
Evaluation of Unsteady Computational Fluid Dynamics Models Applied to the Analysis of a Transonic High-Pressure Turbine Stage
,”
Proc. Inst. Mech. Eng.
, Part A,
228
(
7
), pp.
813
824
.
24.
Rubechini
,
F.
,
Schneider
,
A.
,
Arnone
,
A.
,
Cecchi
,
S.
, and
Garibaldi
,
P.
,
2012
, “
A Redesign Strategy to Improve the Efficiency of a 17-Stage Steam Turbine
,”
ASME J. Turbomach.
,
134
(
3
), p.
031021
.
25.
McGreeham
,
W. F.
, and
Ko
,
S. H.
,
1989
, “
Power Dissipation in Smooth and Honeycomb Labyrinth Seals
,”
ASME
Paper No. 89-GT-220.
26.
Lengani
,
D.
,
Paradiso
,
B.
,
Marn
,
A.
, and
Göttlich
,
E.
,
2012
, “
Identification of Spinning Mode in the Unsteady Flow Field of a Low Pressure Turbine
,”
ASME J. Turbomach.
,
134
(
5
), p.
051032
.
27.
Parker
,
R.
,
1969
, “
The Relation Between Blade Row Spacing and Potential Flow Interaction Effects in Turbomachines
,”
Proc. Inst. Mech. Eng. - Thermodyn. Fluid Mech. Conv.
, 184(7), pp. 1–8.
28.
Greitzer
,
E. M.
,
1984
, “
An Introduction to Unsteady Flows in Turbomachines
,”
NATO Conference on Turbomachinery
, pp.
8.1.1
8.1.58
.
You do not currently have access to this content.