Open rotor pylon fairing
An aircraft defining a longitudinal centerline and extending between a forward end and an aft end is provided. The aircraft comprises a fuselage extending between the forward end of the aircraft and the aft end of the aircraft; a wing assembly extending laterally outwardly with respect to the longitudinal centerline from a portion of the fuselage; an unducted turbofan engine including an unducted fan defining a fan diameter; and a pylon fairing that connects the unducted turbofan engine to the wing assembly, the pylon fairing defining a leading edge and including a first inflection point along the leading edge, the first inflection point defining a first radius of curvature that is less than 5 times the fan diameter and greater than 0.1 times the fan diameter.
1. An aircraft defining a longitudinal centerline and extending between a forward end and an aft end, the aircraft comprising:
a fuselage extending between the forward end of the aircraft and the aft end of the aircraft;
a wing assembly extending laterally outwardly with respect to the longitudinal centerline from a portion of the fuselage;
an unducted turbofan engine including an unducted fan defining a fan diameter and including fan blades rotatable about the longitudinal centerline and fan guide vanes not rotatable about the longitudinal centerline; and
a pylon fairing that connects the unducted turbofan engine to the wing assembly, the pylon fairing having a forwardmost point upstream of a trailing edge of the fan guide vanes, the pylon fairing defining a leading edge and including a first inflection point along the leading edge, the first inflection point defining a first radius of curvature that is less than 5 times the fan diameter and greater than 0.1 times the fan diameter to reduce drag associated with supersonic flow at cruise conditions, and a second inflection point along the leading edge downstream of the first inflection point, the second inflection point defining a second radius of curvature that is less than 3 times the fan diameter and greater than 0.1 times the fan diameter to provide control of a flow of air over the leading edge of the pylon fairing into the wing assembly.
2. The aircraft of claim 1 , wherein the first inflection point is located at a position closer to the unducted turbofan engine than the wing assembly.
3. The aircraft of claim 1 , wherein the pylon fairing includes a cantilevered stator vane.
4. The aircraft of claim 1 , wherein the leading edge of the pylon fairing defines a duckbill shape.
5. The aircraft of claim 1 , wherein the pylon fairing includes a third inflection point along the leading edge downstream of the second inflection point, the third inflection point defining a third radius of curvature that is less than 3 times the fan diameter and greater than 0.1 times the fan diameter.
6. An open rotor pylon system for an aircraft defining a longitudinal centerline and extending between a forward end and an aft end, the aircraft comprising a fuselage extending between the forward end of the aircraft and the aft end of the aircraft; a wing assembly extending laterally outwardly with respect to the longitudinal centerline from a portion of the fuselage; and an unducted turbofan engine including an unducted fan defining a fan diameter and including fan blades rotatable about the longitudinal centerline and fan guide vanes not rotatable about the longitudinal centerline, the open rotor pylon system comprising:
a pylon fairing that connects the unducted turbofan engine to the wing assembly, the pylon fairing having a forwardmost point upstream of a trailing edge of the fan guide vanes, the pylon fairing defining a leading edge and including a first inflection point along the leading edge, the first inflection point defining a first radius of curvature that is less than 5 times the fan diameter and greater than 0.1 times the fan diameter to reduce drag associated with supersonic flow at cruise conditions, and a second inflection point along the leading edge downstream of the first inflection point, the second inflection point defining a second radius of curvature that is less than 3 times the fan diameter and greater than 0.1 times the fan diameter to provide control of a flow of air over the leading edge of the pylon fairing into the wing assembly.
7. The open rotor pylon system of claim 6 , wherein the first inflection point is located at a position closer to the unducted turbofan engine than the wing assembly.
8. The open rotor pylon system of claim 6 , wherein the pylon fairing includes a cantilevered stator vane.
9. The open rotor pylon system of claim 6 , wherein the leading edge of the pylon fairing defines a duckbill shape.
10. The open rotor pylon system of claim 6 , wherein the pylon fairing includes a third inflection point along the leading edge downstream of the second inflection point, the third inflection point defining a third radius of curvature that is less than 3 times the fan diameter and greater than 0.1 times the fan diameter.
11. An aircraft defining a longitudinal centerline and extending between a forward end and an aft end, the aircraft comprising:
a fuselage extending between the forward end of the aircraft and the aft end of the aircraft;
a wing assembly extending laterally outwardly with respect to the longitudinal centerline from a portion of the fuselage;
an unducted turbofan engine including an unducted fan defining a fan diameter and including fan blades and an outlet guide vane having a leading edge and a trailing edge, wherein the fan blades are rotatable about the longitudinal centerline and the outlet guide vane is not rotatable about the longitudinal centerline; and
a pylon fairing that connects the unducted turbofan engine to the wing assembly, the pylon fairing having a forwardmost point upstream of the trailing edge of the outlet guide vane, wherein the pylon fairing defines a pylon fairing leading edge and includes a first inflection point along the pylon fairing leading edge, the first inflection point defining a first radius of curvature that is less than 5 times the fan diameter and greater than 0.1 times the fan diameter to reduce drag associated with supersonic flow at cruise conditions, and a second inflection point along the pylon fairing leading edge downstream of the first inflection point, the second inflection point defining a second radius of curvature that is less than 3 times the fan diameter and greater than 0.1 times the fan diameter to provide control of a flow of air over the pylon fairing leading edge into the wing assembly.
12. The aircraft of claim 11 , wherein the unducted turbofan engine includes a forward compressor frame having a mount, and the forwardmost point of the pylon fairing is upstream of the mount.
13. The aircraft of claim 12 , wherein the forwardmost point of the pylon fairing covers the mount of the forward compressor frame.
14. The aircraft of claim 11 , wherein the forwardmost point of the pylon fairing extends to an inlet lip of the unducted turbofan engine.
15. The aircraft of claim 11 , wherein the pylon fairing includes a rearmost point that extends to a core nozzle exit of the unducted turbofan engine.
16. The aircraft of claim 11 , wherein the unducted turbofan engine includes an unducted rotating element.