Apparatus for eliminating compressor stator vibration induced by tip leakage vortex bursting

Abstract

Vibration induced compressor vane failure from tip leakage vortex bursting is eliminated or minimized. By securing the vane at opposite ends to inner and outer stationary casings, tip leakage is entirely avoided hence avoiding the mechanism for inducing vibration. By contouring the inner surface of the flow path to converge the flow in a downstream direction with a cantilevered compressor vane having a vane tip spaced from the inner casing surface, airflow lift off is precluded or minimized maintaining the flow attached to the flowpath surfaces with consequent avoidance of tip vortex induced vibration.

1 . A compressor comprising: 
 inner and outer stationary casings; and    a plurality of stator vanes extending between and secured at radially opposite ends to said inner and outer casings thereby eliminating tip leakage between opposite sides of each stator vane and stator vane vibration induced by tip leakage vortex bursting.    
   
   
       2 . A compressor comprising: 
 a stator vane segment including a plurality of stator blades and inner and outer stationary shrouds about the blades secured to inner and outer ends of the blades respectively, thereby eliminating tip leakage along the inner shroud and between opposite sides of inner ends of the stator blades.    
   
   
       3 . A compressor according to  claim 2  wherein the inner and outer shrouds define a convergent flow path between adjacent stator blades to minimize or eliminate flow lift off from at least one of said inner and outer surfaces.  
   
   
       4 . A compressor according to  claim 3  wherein the inner shroud has upstream and downstream surfaces, said downstream surfaces extending radially outwardly relative to an axis of the compressor a greater distance than upstream surfaces enabling a convergent flow path.  
   
   
       5 . A compressor comprising: 
 a stator vane segment including a plurality of stator blades and a radial outer shroud, and a stationary inner casing spaced from a tip of the stator blades and having a contoured surface exposed to the flow path for converging the flow in a downstream direction.