Effects of mistuning on blade torsional flutterAn analytical model for the prediction of fan blade flutter is presented and evaluated using data from NASA tests on an advanced high performance engine. For the cascade conditions appropriate to the test points studied, the aerodynamic theory cannot predict subcritical flutter. Under the assumptions of a tuned assembly, the imaginary part of the aerodynamic coefficients does indicate flutter for a limited number of interblade phase angles, but these interblade phase angles are close to those at which the acoustic resonance is predicted. Upon using the individual blade frequencies and solving the mistuned system with aerodynamic coupling only, the results show a stable system. Eigenvectors calculated for the mistuned system demonstrate the presence of several harmonics in each mistuned mode. Inclusion of both mechanical and aerodynamic coupling in the solution of the eigenproblem influences not only the frequencies but also damping in the system with a trend toward stability.
Document ID
19810044691
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Srinivasan, A. V. (United Technologies Research Center East Hartford, Conn., United States)
Kurkov, A. (NASA Lewis Research Center Cleveland, Ohio, United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1981
Subject Category
Structural Mechanics
Meeting Information
Meeting: International Symposium on Air Breathing Engines