Blade excitation by aerodynamic instabilities - A compressor blade study


Conference Paper

In this paper, we investigate non-synchronous vibrations (NSV) in turbomachinery, an aeromechanic phenomenon in which rotor blades are driven by a fluid dynamic instability. Unlike flutter, a self-excited vibration in which vibrating rotor blades and the resulting unsteady aerodynamic forces are mutually reinforcing, NSV is primarily a fluid dynamic instability that can cause large amplitude vibrations if the natural frequency of the instability is near the natural frequency of the rotor blade. In this paper, we present both experimental and computational data. Experimental data was obtained from a full size compressor rig where the instrumentation consisted of blade-mounted strain gages and case-mounted unsteady pressure transducers. The computational simulation used a three-dimensional Reynolds averaged Navier-Stokes (RANS) time accurate flow solver. The computational results suggest that the primary flow features of NSV are a coupled suction side vortex shedding and a tip flow instability. The simulation predicts a fluid dynamic instability frequency that is in reasonable agreement with the experimentally measured value.

Full Text

Duke Authors

Cited Authors

  • Kielb, RE; Thomas, JP; Barter, JW; Hall, KC

Published Date

  • December 1, 2003

Published In

  • American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) Igti

Volume / Issue

  • 4 /

Start / End Page

  • 399 - 406

Digital Object Identifier (DOI)

  • 10.1115/GT2003-38634

Citation Source

  • Scopus