Compressor shroud reverse bleed holes

摘要

A gas turbine engine compressor (20) includes a rotor (24) defining a central axis of rotation and a plurality of blades (28) which project into an annular compressor gas flow passage (42), and a shroud (32) circumferentially surrounding the rotor (24) and having a radially inner surface adjacent to the blade tips (130). Bleed holes (36) extend through the shroud (32) adjacent the blade tips (30), each of the bleed holes (36) having an inlet end (33) disposed in the shroud radially inner surface (34) and an outlet end (35) disposed in a shroud radially outer surface (40). Bleed air removed from the annular gas flow passage (42) flows through the bleed holes (36) from the inlet (33) to the outlet ends (35). The outlet end (35) of each bleed hole (36) is located circumferentially upstream of the inlet end (33) relative to a direction of rotational flow in the annular gas flow passage (42) driven by a direction of rotation of the rotor (24).