Patent ID: 8235648
Filing Date: 2012-08-07
Classification: F02C,F04D,F05D

Abstract:
1. A method of increasing a surge margin of a diffuser of a centrifugal compressor for a gas turbine engine, the diffuser including a diffuser case and a plurality of vanes defining therebetween a plurality of circumferentially distributed angled diffuser passages for receiving gas flow from the centrifugal compressor and an inlet space surrounding an exit of the centrifugal compressor and disposed between said diffuser passages and the centrifugal compressor, the method comprising passively bleeding air from a bleed port in each of said diffuser passages, the bleed port being disposed downstream of a leading edge of the vane defining said diffuser passage and upstream of a throat of said diffuser passage, and passively returning the air bled from the bleed port back into the gas flow at a point upstream of the bleed port and of the leading edge of said vane by reintroducing the bled air into the inlet space for recirculation through said diffuser.