GEARED TURBOFAN WITH THREE TURBINE SECTIONS

摘要

A gas turbine engine comprises a fan rotor configured to be driven by a fan drive turbine through a first shaft and a gear reduction. The fan rotor is configured to deliver air into a bypass duct as bypass air and to deliver core air flow into a core engine where it reaches an upstream compressor rotor. The upstream compressor rotor is configured to be driven through a second shaft by an intermediate turbine rotor. A downstream compressor rotor is configured to be driven by an upstream turbine rotor through a third shaft. An overall pressure ratio across the upstream and downstream compressor rotors is greater than or equal to about 35.0 and less than or equal to about 75.0.