The effect of the structural coupling in the aeroelastic stability of a packet of low-pressure turbine vanes is studied in detail. The dynamics of a 3D sector vane is reduced to that of a simplified mass-spring model to enhance the understanding of its dynamics and to perform sensitivity studies. It is concluded that the dynamics of the simplified model retains the basic features of the finite element three-dimensional model. A linear fully coupled analysis in the frequency domain of the 3D vane sector has been conducted. It is concluded that the small structural coupling provided by the casing and the inter-stage seal is essential to explain the experimental evidences. It is shown that the use of fully coupled aero/structural methods is necessary to retain the mode interaction that takes place in this type of configurations.

References

References
1.
Corral
,
R.
,
Gallardo
,
J.
, and
Vasco
,
C.
, 2007, “
Aeroelastic Stability of Welded-in-Pair Low Pressure Turbine Rotor Blades: A Comparative Study Using Linear Methods
,”
ASME J. Turbomach.
,
129
, pp.
72
83
.
2.
Whitehead
,
D. S.
and
Evans
,
D.
, 1992, “
Flutter of Grouped Turbine Blades
,”
ASME Paper 92-GT-227, Proceedings of the 37th ASME Gas Turbine and Aero Engine Congress, Exposition and Users Symposium
, June 1992, Cologne, Germany.
3.
Kahl
,
G.
, 1995, “
Application of the Time Linearized Euler Method to Flutter and Forced Response Calculations
,”
ASME Paper 95-GT-123, Proceedings of the 40th ASME Gas Turbine and Aero Engine Congress, Exposition and Users Symposium
, June 1995, Houston, Texas.
4.
Chernysheva
,
O. V.
,
Fransson
,
T. H.
,
Kielb
,
R. E.
, and
Barter
,
J.
, 2003, “
Effect of Sector Mode Shape Variation on the Aerodynamic Stability of a Low-Pressure Turbine Sectored Vane
,”
ASME Paper 2003-GT-38632, Proceedings of the 48nd ASME Gas Turbine and Aero engine Congress, Exposition and Users Symposium
, June 2003, Atlanta, Georgia.
5.
Corral
,
R.
,
Gallardo
,
J. M.
, and
Martel
,
C.
, 2009, “
A Conceptual Flutter Analysis of a Packet of Vanes Using a Mass-Spring Model
,”
ASME J. Turbomach.
,
131
, pp.
021016
-1−
7
.
6.
Panovsky
,
J.
, and
Kielb
,
R.
, 2000, “
A Design Method to Prevent Low Pressure Turbine Blade Flutter
,”
ASME J. Eng. Gas Turbines and Power
,
122
, pp.
89
98
.
7.
Nowinski
,
M.
, and
Panovsky
,
J.
, 2000, “
Flutter Mechanisms in Low Pressure Turbine Blades
,”
ASME J. Eng. Gas Turbines and Power
,
122
, pp.
82
88
.
8.
Smith
,
D.
, 1948, “
Vibration of Turbine Blades in Packets
,”
Proceedings of the 7th Conference for Applied Mechanics
,
3
, p.
178
.
9.
Prohl
,
M.
, 1958, “
A Method for Calculating Vibration Frequency and Stress of a Banded Group of Turbine Buckets
,”
Trans. ASME
,
80
, pp.
169
175
.
10.
Rao
,
J.
, 1991,
Turbomachine Blade Vibration
,
John Wiley & Sons, Inc.
,
New York
.
11.
Corral
,
R.
,
Escribano
,
A.
,
Gisbert
,
F.
,
Serrano
,
A.
, and
Vasco
,
C.
, 2003, “
Validation of a Linear Multigrid Accelerated Unstructured Navier-Stokes Solver for the Computation of Turbine Blades on Hybrid Grids
,”
AIAA Paper 2003–3326, 9th AIAA/CEAS Aeroacoustics Conference
, May 2003, Hilton Head, South Carolina.
12.
Corral
,
R.
, and
Gallardo
,
J.
, 2008, “
Verification of the Vibration Amplitude Prediction of Self-Excited LPT Rotor Blades Using a Fully Coupled Time-Domain Non-Linear Method and Experimental Data
,”
ASME Paper 2008-GT-51416, Proceedings of the 51st ASME Gas Turbine and Aero Engine Congress, Exposition and Users Symposium
, June 2008, Berlin, Germany.
13.
Feiner
,
D. M.
, and
Griffin
,
J. H.
, 2002, “
A Fundamental Model of Mistuning for a Single Family of Modes
,”
ASME J. Turbomach.
,
124
, pp.
597
605
.
14.
Martel
,
C.
,
Corral
,
R.
, and
Llorens
,
J. M.
, 2008, “
Stability Increase of Aerodynamically Unstable Rotors Using Intentional Mistuning
,”
ASME J. Turbomach.
,
130
, p.
011006
.
You do not currently have access to this content.