An apparatus is provided for an aircraft propulsion system. This apparatus includes an exhaust nozzle. The exhaust nozzle includes a flowpath, a passage, an outer door, an inner door and an actuator configured to move the outer door and the inner door between an open arrangement and a closed arrangement. The flowpath extends axially along a centerline through the exhaust nozzle. The passage extends laterally into the exhaust nozzle to the flowpath when the outer door and the inner door are in the open arrangement. The outer door is configured to pivot inwards towards the centerline when the outer door moves from the closed arrangement to the open arrangement. The inner door is configured to pivot outwards away from the centerline when the inner door moves from the closed arrangement to the open arrangement.

Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

In a cowl for a nozzle, an internal wall has a cross-section with a determined abscissa on the axis defining a neck line on the internal wall. The cowl has, downstream of the determined abscissa, indentations in the trailing edge which delimit chevrons distributed in the circumferential direction. The internal wall of the cowl diverges radially towards the interior, in a second axial half-plane passing through the tip of a chevron, from the upstream tangent on the point of the neck line in the second axial half-plane, and the lines defining the internal wall of the cowl in any axial half-plane do not have a turning point downstream of the determined abscissa of the neck line.

In a cowl for a nozzle, an internal wall has a cross-section with a determined abscissa on the axis defining a neck line on the internal wall. The cowl has, downstream of the determined abscissa, indentations in the trailing edge which delimit chevrons distributed in the circumferential direction. The internal wall of the cowl diverges radially towards the interior, in a second axial half-plane passing through the tip of a chevron, from the upstream tangent on the point of the neck line in the second axial half-plane, and the lines defining the internal wall of the cowl in any axial half-plane do not have a turning point downstream of the determined abscissa of the neck line.

An unducted thrust producing system has a rotating element with an axis of rotation and a stationary element. The rotating element includes a plurality of blades, each having a blade root proximal to the axis, a blade tip remote from the axis, and a blade span measured between the blade root and the blade tip. The rotating element has a load distribution such that at any location between the blade root and 30% span the value of ΔRCu in the air stream is greater than or equal to 60% of the peak ΔRCu in the air stream.

An unducted thrust producing system has a rotating element with an axis of rotation and a stationary element. The rotating element includes a plurality of blades, each having a blade root proximal to the axis, a blade tip remote from the axis, and a blade span measured between the blade root and the blade tip. The rotating element has a load distribution such that at any location between the blade root and 30% span the value of ΔRCu in the air stream is greater than or equal to 60% of the peak ΔRCu in the air stream.

Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

A gas turbine is provided, the gas turbine engine including a turbomachine having an inlet splitter defining in part an inlet to a working gas flowpath and a fan duct splitter defining in part an inlet to a fan duct flowpath. The gas turbine engine also includes a primary fan driven by the turbomachine defining a primary fan tip radius R1, a primary fan hub radius R2, and a primary fan specific thrust rating TP; and a secondary fan downstream of the primary fan and driven by the turbomachine, the secondary fan defining a secondary fan tip radius R3, a secondary fan hub radius R4, and a secondary fan specific thrust rating TS; wherein the gas turbine engine defines an Effective Bypass Area, and wherein a ratio of R1 to R3 equals $\frac{R_1}{R_3}=\sqrt{\left(EFP\right)\frac{\left(1-{\mathrm{RqR}}_{\mathrm{Sec}.-\mathrm{Fan}}^2\right)}{\left(1-{\mathrm{RqR}}_{\mathrm{Prim}.-\mathrm{Fan}}^2\right)}\left(\frac{T_P}{T_S}\right)\left(EBA\right)}.$