Ceramic matrix composites (CMCs) provide several benefits over metal blades including weight and increased temperature capability, and have the potential for increased engine performance by reduction of the cooling flow bled from the compressor and by allowing engines to run at higher turbine inlet temperatures. These CMC blades must be capable of surviving fatigue (high cycle and low cycle), creep, impact, and any tip rub events due to the engine missions or maneuvers that temporarily close blade tip/shroud clearances. As part of a cooperative research program between GE Aviation and the Ohio State University Gas Turbine Laboratory, OSU GTL, the response of a CMC stage 1 low-pressure turbine blade has been compared with the response of an equivalent metal turbine blade using the OSU GTL large spin-pit facility (LSPF) as the test vehicle. Load cells mounted on the casing wall, strain gages mounted on the airfoils, and other instrumentation are used to assess blade tip rub interactions with a 120-deg sector of a representative turbine stationary casing. The intent of this paper is to present the dynamic response of both the CMC and the metal blades with the turbine disk operating at design speed and with representative incursion rates and depths. Casing wear and blade tip wear are both characterized for several types of rub conditions including a light, medium, and heavy rub at room temperature. For each condition, the rub primary dynamic modes have been evaluated, and the corresponding blade tip loads have been calculated. The preliminary results suggest that a CMC blade has similar abilities to a metal blade during a rub event.

References

References
1.
Manwaring
,
S. R.
, and
Wisler
,
D. C.
,
1993
, “
Unsteady Aerodynamics and Gust Response in Compressors and Turbines
,”
ASME J. Turbomach.
,
115
(
4
), pp.
724
740
.10.1115/1.2929308
2.
Weaver
,
M. M.
,
Manwaring
,
S. R.
,
Abhari
,
R. S.
,
Dunn
,
M. G.
,
Salay
,
M. J.
,
Frey
,
K. K.
, and
Heidegger
,
N.
,
2000
, “
Forcing Function Measurements and Predictions of a Transonic Vaneless Counter Rotating Turbine
,”
ASME
Paper No. 2000-GT-0375. 10.1115/2000-GT-0375
3.
Kielb
,
J. J.
,
Abhari
,
R. S.
, and
Dunn
,
M. G.
,
2001
, “
Experimental and Numerical Study of Forced Response in a Full-Scale Rotating Turbine
,”
ASME
Paper No. 2001-GT-0263.10.1115/2001-GT-0263
4.
Yigit
,
A.
,
Ulsoy
,
A. G.
, and
Scott
,
R. A.
,
1990
, “
Dynamics of a Radially Rotating Beam With Impact
,”
ASME J. Vib. Acoust. Stress Reliab. Des.
,
112
(1), pp.
71
77
.10.1115/1.2930101
5.
Jiang
,
J.
,
Ahrens
,
J.
,
Ulbrich
,
H.
, and
Scheideler
,
E. M.
,
1998
, “
A Contact Model of a Rotating Rubbing Blade
,”
5th International Conference on Rotor Dynamics
,
Darmstadt, Germany
, Sept. 7–10, pp.
478
489
.
6.
Ahrens
,
J.
,
Ulbrich
,
H.
, and
Ahaus
,
G.
,
2000
, “
Measurement of Contact Forces During Blade Rubbing
,”
7th ImechE International Conference of Vibrations in Rotating Machinery, Nottingham, UK, Sept. 12–14
, pp.
259
263
.
7.
Sinha
,
S. K.
,
2005
, “
Non-Linear Dynamic Response of a Rotating Radial Timoshenko Beam With Periodic Pulse Loading at the Free-End
,”
Int. J. Non-Linear Mech.
,
40
(
1
), pp.
113
149
.10.1016/j.ijnonlinmec.2004.05.019
8.
Young
,
G.
,
2006
, “
Development of a General Predictive Model for Blade Tip/Shroud Interference; Interactive Forces
,” Master's thesis, The Ohio State University, Columbus, OH.
9.
Ferguson
,
J.
,
2008
, “
A Moving Load Finite Element-Based Approach to Determining Blade Tip Forces During a Blade-on-Casing Incursion in a Gas Turbine Engine
,” Master's thesis, The Ohio State University, Columbus, OH.
10.
Turner
,
K.
,
Dunn
,
M. G.
, and
Padova
,
C.
,
2010
, “
Airfoil Deflection Characteristics During Rub Events
,”
ASME
Paper No. GT2010-22166.10.1115/GT2010-22166
11.
Padova
,
C.
,
Dunn
,
M. G.
,
Barton
,
J.
,
Turner
,
K.
,
Turner
,
A.
, and
DiTommaso
,
D.
,
2011
, “
Casing Treatment and Blade-Tip Configuration Effects on Controlled Gas Turbine Blade Tip/Shroud Rubs at Engine Conditions
,”
ASME J. Turbomach.
,
133
(
1
), p.
011016
.10.1115/1.4000539
12.
Corman
,
G. S.
, and
Luthra
,
K. L.
,
2005
, “
Silicon Melt Infiltrated Ceramic Composites (HiPerComTM)
,”
Handbook of Ceramic Composites
,
N. P.
Bansal
, ed.,
GE Global Research Center
,
Niskayuna, NY
, Chap. 5.
13.
Luthra
,
K. L.
,
2002
, “
Melt Infiltrated (MI) SiC/SiC Composites for Gas Turbine Applications
,” DER Peer Review for Microturbine and Industrial Gas Turbines Programs, Fairfax, VA, Mar. 12–14, available at: http://infohouse.p2ric.org/ref/20/19293.pdf
14.
Reynaud
,
P.
,
1996
, “
Cyclic Fatigue of Ceramic–Matrix Composites at Ambient and Elevated Temperatures
,”
Compos. Sci. Technol.
,
56
(
7
), pp.
809
814
.10.1016/0266-3538(96)00025-5
15.
NiDI
,
1995
,
High-Temperature High-Strength Nickel Base Alloys
, Nickel Develoment Institute, Toronto, Canada, Supplement No. 393, pp.
2
52
.
16.
Pallot
,
G.
,
Kato
,
D.
,
Kodama
,
H.
,
Matsuda
,
K.
,
Taniguchi
,
H.
,
Kato
,
H.
,
Funazaki
,
K.-i.
,
2011
, “
The Effect of the Casing Movement Relative to the Blades on the Tip Leakage Loss in Axial Flow Compressors
,”
ASME
Paper No. GT2011-46182.10.1115/GT2011-46182
17.
Garza
,
J. W.
,
2006
, “
Tip Rub Induced Blade Vibrations: Experimental and Computational Results
,” Master's thesis, The Ohio State University, Columbus, OH.
18.
Faucett
,
D. C.
, and
Choi
,
S. R.
,
2011
, “
Strength Degradation of Oxide/Oxide and SiC/SiC Ceramic Matrix Composites in CMAS and CMAS/SALT Exposures
,”
ASME
Paper No. GT2011-46771.10.1115/GT2011-46771
You do not currently have access to this content.