The work described in this paper is part of a comprehensive research effort aimed at eliminating the occurrence of low pressure turbine blade flutter in aircraft engines. The results of fundamental unsteady aerodynamic experiments conducted in an annular cascade are studied in order to improve the overall understanding of the flutter mechanism and to identify the key flutter parameters. In addition to the standard traveling wave tests, several other unique experiments are described. The influence coefficient technique is experimentally verified for this class of blades. The beneficial stabilizing effect of mistuning is also directly demonstrated. Finally, the key design parameters for flutter in low pressure turbine blades are identified. In addition to the experimental effort, correlating analyses utilizing linearized Euler methods demonstrate that these computational techniques are adequate to predict turbine flutter. [S0742-4795(00)01301-6]

Issue Section:
Gas Turbines: Structures and Dynamics
Keywords:
aircraft, engines, gas turbines, vibrations, aerodynamics, cascade systems, stability, damping, pressure measurement, testing
Topics:
Blades, Cascades (Fluid dynamics), Pressure, Flutter (Aerodynamics), Damping, Traveling waves, Design, Stability, Turbine blades
1.
Bo¨lcs, A., and Schla¨fli, D., 1984, “Flutter Phenomena in a Transonic Turbine Cascade,” Unsteady Aerodynamics of Turbomachines and Propellers, Proceedings, Symposium, Cambridge, England, pp. 411–425, September 24–27, 1984.
2.
Buffum, D. H., and Fleeter, S., 1990, “Aerodynamics of a Linear Oscillating Cascade,” NASA Technical Memorandum 103250.
3.
Panovsky, J., Nowinski, M., and Bo¨lcs, A., 1997, “Flutter of Aircraft Engine Low Pressure Turbine Blades,” presented at the 8th International Symposium of Unsteady Aerodynamics and Aeroelasticity of Turbomachines, Stockholm, Sweden, Sept. 14–18, 1997.
4.
Bo¨lcs, A., 1983, “A Test Facility for the Investigation of Steady and Unsteady Transonic Flows in Annular Cascades,” ASME Paper 83-GT-34.
5.
Kirschner, A., Fosco, B., and Muller, E., 1980, “Control of Vibration in Aeroelastic Experiments,” Communication de l’ITA/EPFL, No. 10, pp. 285–295.
6.
Holmes, D. G., and Chuang, H. A., 1993, “2D Linearized Harmonic Euler Flow Analysis for Flutter and Forced Response,” in Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines and Propellers, H. M. Atassi, ed., Springer-Verlag, New York.
7.
Bo¨lcs, A., and Fransson, T. H., 1986, “Aeroelasticity in Turbomachines: Comparison of Theoretical and Experimental Cascade Results,” Air Force Office of Scientific Research, AFOSR-TR-87-0605.
8.
Panovsky, J., 1997, “Flutter of Aircraft Engine Turbine Blades,” Ph.D. dissertation, University of Cincinnati, Cincinnati, OH.
9.
Lane, F., 1956, “System Mode Shapes in the Flutter of Compressor Blade Rows,” J. Aeronaut. Sci., pp. 54–66.
10.
Crawley, E. F., 1998, “Aeroelastic Formulation for Tuned and Mistuned Rotors,” chapter 19 in AGARD Manual on Aeroelasticity in Axial-Flow Turbomachines, Vol. 2, Structural Dynamics and Aeroelasticity, M. F. Platzer and F. O. Carta, eds., AGARD-AG-298.
11.
Crawley
,
E. F.
, and
Hall
,
K. C.
,
1985
, “
Optimization and Mechanisms of Mistuning in Cascades
,”
ASME J. Eng. Gas Turbines Power
,
107
, No.
2
, pp.
418
–
426
.
12.
Ko¨rba¨cher, H., 1996, “Experimental Investigation of the Unsteady Flow in an Oscillating Annular Compressor Cascade,” Ph.D. dissertation, Laboratoire de Thermique applique´e et de Turbomachines, Swiss Federal Institute of Technology, Lausanne, Switzerland.
13.
Bo¨lcs, A., Fransson, T. H., and Schla¨fli, D., 1989, “Aerodynamic Superposition Principle in Vibrating Turbine Cascades,” presented at the AGARD 74th Specialists’ Meeting of the Propulsion and Energetics Panel on Unsteady Aerodynamic Phenomena in Turbomachines, Luxembourg, August 28–September 1, 1989.
14.
Ko¨rba¨cher, H., and Bo¨lcs, A., 1996, “Steady-State and Time-Dependent Experimental Results of a NACA-3506 Cascade in an Annular Channel,” ASME Paper 96-GT-334.
15.
Kaza
,
K. R. V.
, and
Kielb
,
R. E.
,
1982
, “
Flutter and Response of a Mistuned Cascade in Incompressible Flow
,”
AIAA J.
,
20
, No.
8
, pp.
1120
–
1127
.
16.
Zweifel
,
O.
,
1945
, “
The Spacing of Turbomachinery Blading. Especially with Large Angular Deflection
,”
Brown Boveri Rev.
, Vol.
32
, p.
12
12
.
17.
Panovsky, J., and Kielb, R., 1998, “A Design Method to Prevent Low Pressure Turbine Blade Flutter,” presented at the ASME Gas Turbine Conference and Exhibition, Stockholm, Sweden, June, 1998.
Copyright © 2000
 by ASME
You do not currently have access to this content.