| 摘要 |
<p>The surge margin of a fan or compressor stage may be increased by radial, circular grooves in the casing ( 2 ) encircling the rotor stage. The present invention provides improved aerodynamic performance by replacing circumferential grooves by multiple helical grooves 18 . Preferably the grooves ( 18 ) have multiple start and end positions ( 20,22 ) spaced apart around the casing ( 2 ) and at least the downstream ends ( 22 ) of the grooves ( 18 ) are tapered to aid expulsion of particles in the grooves ( 18 ).</p> |
