TURBINE ENGINE WITH COOLED P3 AIR TO IMPELLER REAR CAVITY

摘要

An air distribution system for an impeller rear cavity (30), including an air bleed (46) at the compressor impeller (22) tip for bleeding pressurized air into the rear cavity, and a second stream of P3 air is passed into the rear cavity area (30) after having been cooled by a heat exchanger (36). The mixing of the cooled P3 air (46) with the bleed air from the impeller tip reduces the temperature of the pressurized air in the rear cavity to reduce degradation of the impeller as well as to provide a flow of cooling air for the central bearing.