In the dynamics of turbomachinery, the mechanical damping of the blading has been the focus of research for the last decades to improve the dynamic performance in terms of high cycle fatigue issues. In addition, an increased mechanical damping can produce a higher flutter safety margin such that stable operation conditions are achievable in a bigger range. Hence, novel damping techniques are considered besides the well known friction based damping devices. In this paper, an extended analysis of the eddy current based damping device for a last stage steam turbine blading presented in GT2009-59593 is conducted. A transient electromagnetic finite element analysis of the eddy current damper is performed, and the resulting damping forces are compared to their analytical solution. Parameter studies are carried out, and equivalent damping factors are calculated. Furthermore, for the validation of the finite element model, a test rig was built that allows for the direct measurement of damping forces when forcing a sinusoidal relative motion. Forced response measurements and simulations are used to demonstrate its dynamic performance and predictability.

References

References
1.
Swedowicz
,
J.
, 2010, “
30-Year Anniversary of Friction Damper Technology in Turbine Blades
,” ASME, Mechanical Engineering.
2.
Yang
,
B.-D.
, and
Menq
,
C.-H.
, 1997, “
Modeling of Friction Contact and its Application to the Design of Shroud Contact
,”
ASME J. Eng. Gas Turbines Power
,
119
(
4
), pp.
958
–963,.
3.
Griffin
,
J. H.
, 1980, “
Friction Damping of Resonant Stresses in Gas Turbine Engine Airfoils
,”
J. Eng. Power
,
102
, pp.
329
333
.
4.
Sanliturk
,
K.
,
Ewins
,
D.
, and
Stanbridge
,
A.
, 2001, “
Underplatform Dampers for Turbine Blades: Theoretical Modeling, Analysis, and Comparison With Experimental Data
,”
ASME J. Eng. Gas Turbines Power
,
123
, pp.
919
929
.
5.
Panning
,
L.
,
Popp
,
K.
,
Sextro
,
W.
,
Götting
,
F.
,
Kayser
,
A.
, and
Wolter
,
I.
, 2004, “
Asymmetrical Underplatform Dampers in Gas Turbine Bladings: Theory and Application
,” Transactions of the ASME Turbo Expo, Vienna, 2004.
6.
Laxalde
,
D.
,
Gibert
,
C.
, and
Thouverez
,
F.
, 2008, “
Experimental and Numerical Investigations of Friction Ring Damping of Blisks
,”
Proceedings of the ASME Turbo Expo
, Berlin, 2008.
7.
Chen
,
J. J.
, and
Meng
,
C. H.
, 1999, “
Prediction of Periodic Response of Blades Having 3d Shroud Constraints
,” Transactions of the ASME Turbo Expo, Orlando, 2009.
8.
Sextro
,
W.
, 2000, “
The Calculation of Forced Response of Shrouded Blades With Friction Contacts and its Experimental Verification
,”
Proceedings of the ASME Turbo Expo
, Munich, 2000.
9.
Firrone
,
C.
,
Allara
,
M.
, and
Gola
,
M.
, 2008, “
A Contact Model for Nonlinear Forced Response Prediction of Turbine Blades: Calculation Techniques and Experimental Comparison
,”
Transactions of the ASME Turbo Expo
, Berlin, 2008, Paper 43154, pp.
573
582
.
10.
Filippi
,
S.
,
Rodrigues
,
E. B.
, and
Gola
,
M.
, 2006, “
Experimental Characterization of Contact Hysteresis at High Temperatures
,”
ASME Conference Proceedings Turbo Expo
, Barcelona, 2006.
11.
Salles
,
L.
,
Blanc
,
L.
,
Thouverez
,
F.
, and
Gouskov
,
A.
, 2008, “
Dynamic Analysis of Fretting-Wear in Friction Contact Interfaces
,”
ASME Conference Proceedings Turbo Expo
, Berlin, 2008.
12.
Duffy
,
K. P.
,
Mehmed
,
D.
, and
Johnson
,
O.
, 2001, “
Self-tuning Impact Dampers for Fan and Turbine Blades
,”
6th National Turbine Engine High Cycle Fatigue (HCF) Conference Proceedings
, Dayton.
13.
Sun
,
J.
, and
Kari
,
L.
, 2010, “
Coating Methods to Increase Material Damping of Compressor Blades—Measurements and Modeling
,”
Proceedings of the ASME Turbo Expo
, Glasgow, 2010.
14.
Filippi
,
S.
, and
J.
,
T. P.
, 2010, “
A Methodology for Predicting the Response of Blades With Non-Linear Coatings
,”
ASME Conference Proceedings Turbo Expo
, Glasgow, 2010.
15.
Yen
,
H.-Y.
, and
M.-H.
,
H. S.
, 2001, “
Passive Vibration Suppression of Beams and Blades Using Magnetomechanical Coating
,”
J. Sound Vibr.
,
245
(
4
), pp.
701
714
.
16.
Duffy
,
K. P.
,
Provenza
,
A.
,
Trudell
,
J.
, and
Min
,
J.
, 2009, “
Passively Shunted Piezoelectric Damping of Centrifugally Loaded Plates
,”
Proceedings of the 17th AIAA Adaptive Structures Conference
, Palm Springs.
17.
Hohl
,
A.
,
Neubauer
,
M.
,
Schwarzendahl
,
S.
,
Panning
,
L.
, and
Wallaschek
,
J.
, 2009, “
Active and Semiactive Vibration Damping of Turbine Blades With Piezoceramics
,”
Proc. SPIE Smart Structures
,
7288
, p.
72881H
.
18.
Laborenz
,
J.
,
Siewert
,
C.
,
Panning
,
L.
,
Wallaschek
,
J.
,
Gerber
,
C.
, and
Masserey
,
P.
, 2010, “
Eddy Current Damping: A Concept Study for Steam Turbine Blading
,”
ASME J. Eng. Gas Turbines Power
,
132
(
5
), p.
052505
.
19.
Cheng
,
D.
, 1989,
Field and Wave Electromagnetics
,
Prentice-Hall
,
Englewood Cliffs, NJ
.
20.
Albertz
,
D.
,
Dappen
,
S.
, and
Henneberger
,
G.
, 1996, “
Calculation of the 3D Nonlinear Eddy Current Field in Moving Conductors and its Application to Braking Systems
,”
IEEE Trans. Magn.
,
32
(
3
), pp.
768
771
.
21.
Niikura
,
S.
, and
Kameari
,
A.
, 1992, “
Analysis of Eddy Current and Force in Conductors With Motion
,”
IEEE Trans. Magn.
,
28
(
2
), pp.
1450
1453
.
22.
Onuki
,
T.
,
Kamiya
,
Y.
,
Fukaya
,
K.
, and
Jeon
,
W.
, 1999, “
Characteristics Analysis of Linear Induction Motor With Two Types of Secondary Structure Based on Electromagnetic Field and Electric Circuit Analysis
,”
IEEE Trans. Magn.
,
35
(
5
), pp.
4022
4024
.
23.
Wegener
,
R.
, 2008, “
Zylindrischer Linearmotor mit konzentrierten Wicklungen für hohe Kräfte
,” Ph.D. thesis, Technischen Universität Dortmund, Dortmund, Germany.
24.
Vese
,
I.-C.
,
Marignetti
,
F.
, and
Radulescu
,
M.
, 2010, “
Multiphysics Approach to Numerical Modeling of a Permanent-Magnet Tubular Linear Motor
,”
IEEE Trans. Ind. Electron.
,
57
(
1
), pp.
320
326
.
25.
Kurz
,
S.
,
Fetzer
,
J.
, and
Lehner
,
G.
, 1996, “
Three-Dimensional Transient BEM-FEM Coupled Analysis of Electrodynamic Levitation Problems
,”
IEEE Trans. Magn.
,
32
(
3
), pp.
1062
1065
.
26.
Kurz
,
S.
,
Fetzer
,
J.
,
Lehner
,
G.
, and
Rucker
,
W.
, 1999, “
Numerical Analysis of Three-Dimensional Eddy Current Problems With Moving Bodies by Boundary Element-Finite-Element Method Coupling
,”
Surv. Math. Ind.
,
9
(
2
), pp.
131
150
.
27.
Lai
,
H.
,
Rodger
,
D.
, and
Coles
,
P.
, 2004, “
A 3-D Overlapping Finite-Element Scheme for Modeling Movement
,”
IEEE Trans. Magn.
,
40
(
2
), pp.
533
536
.
28.
Rachek
,
M.
, and
Feliachi
,
M.
, 2007, “
3D Transient Analysis and Movement Simulation for the Modelling of Magnetic Levitation
,”
Int. J. Comput. Appl. Technol.
,
30
(
4
), pp.
229
235
.
29.
Ansoft, 2009, “
Ansoft Maxwell 12 Technical Notes
,” Technical Report.
30.
Magnus
,
K.
, and
Popp
,
K.
, 1986, Schwingungen, Teubner, Stuttgart, Germany.
31.
Bae
,
J.
,
Hwang
,
J.
,
Park
,
J.
, and
Kwag
,
D.
, 2009, “
Modeling and Experiments on Eddy Current Damping Caused by a Permanent Magnet in a Conductive Tube
,”
J. Mech. Sci. Technol.
,
23
(
11
), pp.
3024
3035
.
You do not currently have access to this content.