Dynamic control of tip clearance

摘要

A gas turbine engine (10) includes a plurality of rotor blades (24) having a root (33) and a tip (34) and a pressure side (32) and a suction side (30). The rotor blades (24) are enclosed in an engine case (11). A variable position engine case liner (50) is disposed radially inward of the engine case (11) and radially outward of the rotor blade tips (34). Biasing mechanism (60), disposed between the liner (50) and the engine case (11), urge the liner (50) radially inward from the engine case (11). The tips (34) of the rotor blades (24) are angled with respect to the direction of rotation of the blades (24) on the pressure side (32) thereof to deflect pressurized air against the liner (50). The liner (50) adjusts its position to maintain a minimum tip clearance (70) between the liner (50) and the tips (34) of the rotor blades (24) during different operating conditions of the gas turbine engine (10).