Forced response is a critical concern in turbomachinery design, as it can quickly lead to high-cycle fatigue failure. However, for modern compressor design programs, it is virtually impossible to remove all resonant crossings that occur within the operating range of the compressor. One option to mitigate these resonant crossings is to break up the strength of the aerodynamic forcing at particular frequencies through the introduction of stator asymmetry. This work investigates the predicted reduction in strength of the vortical forcing function due to stator asymmetry in a three-stage axial compressor. Stator asymmetry is introduced by modifying stator 1 to have unequal vane counts on each stator half. Steady single-passage computational fluid dynamics simulations are used to build representative full-annulus wake structures of the symmetric and asymmetric geometries using total pressure wake profiles downstream of the stator. A Fourier transform of these wake structures compares the frequencies and strengths of the aerodynamic forcing. The introduction of asymmetry in stator 1 reduces the aerodynamic forcing by shifting the symmetric stator harmonics into neighboring frequencies while also reducing the amplitudes of all harmonics. Unsteady full-annulus aeroelasticity simulations quantify the reduction in aerodynamic forcing and the resulting vibrational response of the embedded rotor due to vortical disturbances from a baseline and asymmetric upstream stator.
Reduction of Aerodynamic Forcing Through Introduction of Stator Asymmetry in Axial Compressors
Journal of Propulsion and Power ; 32 , 1 ; 134-141
2015-09-16
8 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Reduction of Aerodynamic Forcing Through Introduction of Stator Asymmetry in Axial Compressors
Online Contents | 2016
|Aerodynamic design and axial flow compressors
TIBKAT | 1965
|Aerodynamic design and axial flow compressors
SLUB | 1965
|