A flow control system on an aircraft engine nacelle incorporates a plurality of translating turning vanes each having a body. An equal plurality of actuators is coupled to a trailing edge of the body of an associated one of the translating turning vanes. The actuator translates the body from a retracted position to an extended position.

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 (D.sub.t) 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.

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 (D.sub.t) 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.

A gas turbine engine includes a propulsor, a compressor comprising a compressor rotor, and a turbine comprising a turbine rotor fixedly mechanically coupled to the compressor rotor. The propulsor and the compressor are arranged in axial flow series. The turbine rotor is radially outward of the compressor rotor, and the direction of fluid flow through the turbine is generally opposite the direction of gas flow through the propulsor and the compressor.

A propulsion system according to an example of the present disclosure includes, among other things, a geared architecture configured to drive a fan section including a fan, and a turbine configured to drive the geared architecture. The turbine has an exit point, and a diameter (Dt) defined as the radially outer diameter of a last blade airfoil stage in the turbine at the exit point. A nacelle at least partially surrounds a core engine housing. The fan configured to deliver air into a bypass duct is defined between the nacelle and the core engine housing. A core engine exhaust nozzle is downstream of the exit point, with a downstream most point of the core engine exhaust nozzle being defined at a distance (Lc or Ln) from the exit point.

A propulsion system according to an example of the present disclosure includes, among other things, a geared architecture configured to drive a fan section including a fan, and a turbine configured to drive the geared architecture. The turbine has an exit point, and a diameter (Dt) defined as the radially outer diameter of a last blade airfoil stage in the turbine at the exit point. A nacelle at least partially surrounds a core engine housing. The fan configured to deliver air into a bypass duct is defined between the nacelle and the core engine housing. A core engine exhaust nozzle is downstream of the exit point, with a downstream most point of the core engine exhaust nozzle being defined at a distance (Lc or Ln) from the exit point.

A highly efficient gas turbine engine is a system wherein the fan of the gas turbine engine is driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

A gas turbine engine has a compression system radius ratio defined as the ratio of the radius of the tip of a fan blade to the radius of the tip of the most downstream compressor blade in the range of from 5 to 9. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft.

A gas turbine engine has a compression system radius ratio defined as the ratio of the radius of the tip of a fan blade to the radius of the tip of the most downstream compressor blade in the range of from 5 to 9. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft.

A gas turbine engine that has improved fuel burn provides operability and/or maintenance requirements when installed on an aircraft. The gas turbine engine is provided with a core compressor that includes twelve, thirteen or fourteen rotor stages. The gas turbine engine has a ratio of a core compressor aspect ratio divided by a core compressor pressure ratio is in the range of from 0.03 to 0.09. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft.