HIGH EFFICIENCY GEARED TURBOFAN

摘要

A gas turbine engine comprises a fan drive turbine. The fan drive turbine drives the fan through a gear reduction; A change in enthalpy is defined across the gas turbine engine. The change in enthalpy divided by a speed of the fan drive turbine squared is less than or equal to about 1.8. An axial component of gases approaching an upstream most blade of the fan drive turbine divided by the speed of the fan drive turbine is equal to or less than about 0.9.