ELONGATED GEARED TURBOFAN WITH HIGH BYPASS RATIO

摘要

A propulsion system includes a fan, a gear, a turbine configured to drive the gear to, in turn, drive the fan. The turbine has an exit point, and a diameter (Dt) is defined at the exit point. A nacelle surrounds a core engine housing. The fan is configured to deliver air into a bypass duct defined between the nacelle and the core engine housing. A core engine exhaust nozzle is provided downstream of the exit point. A downstream most point of the core engine exhaust nozzle is defined at a distance from the exit point. A ratio of the distance to the diameter is greater than or equal to about 0.90.

主权项

1. A propulsion system comprising:
a fan; a gear; a turbine configured to drive said gear to drive said fan, said turbine having an exit point, and a diameter (Dt) defined as the diameter of a last blade airfoil stage in the turbine at said exit point; a nacelle surrounding a core engine housing, said fan configured to deliver air into a bypass duct defined between said nacelle and said core engine housing; and a core engine exhaust nozzle downstream of said exit point, with a downstream most point of said core engine exhaust nozzle being defined at a distance (Lc or Ln) from the exit point, wherein a ratio of said distance (Lc or Ln) to said diameter (Dt) is greater than or equal to about 0.90.