Patent ID: 8100643

Claim:
A centrifugal compressor vane diffuser for receiving high velocity air from an impeller mounted for rotation about an axis of a gas turbine engine compressor, the diffuser comprising front and back walls defining an axial gap therebetween, a circumferential array of vane islands extending from the front wall to the back wall to define therewith a plurality of vane island passages, the vane islands having leading edges located on an inner circumference and trailing edges located on an outer circumference, the inner and outer circumferences being centered relative to the axis of rotation of the impeller, and a series of low profile flow boundary disrupting protrusions circumferentially staggered relative to said circumferential array of vane islands and disposed in said vane island passages, the low profile flow boundary disrupting protrusions projecting a short distance from one of said front and back walls to a flow boundary region of the vane island passages, each of the flow boundary disrupting protrusions having a chord length extending between a leading edge and a trailing edge, the chord length of the flow boundary disrupting protrusions being smaller than that of the vane islands, the flow boundary disrupting protrusions being contained between said inner and outer circumferences, and the leading edges of the flow boundary disrupting protrusions being located radially outward from said inner circumference.