Dissimilarly shaped aircraft nozzles with tandem mixing devices, and associated systems and methods are disclosed. An ejector nozzle in a representative embodiment includes a nozzle duct having a nozzle flow axis, a first axial position and a second axial position. The nozzle duct has a first cross-sectional shape at the first axial position, and a second cross-sectional shape at the second axial position, with the second shape being geometrically non-similar to the first shape. The nozzle further includes a fan flow duct portion and a core flow duct portion, both upstream of the first axial position. An ejector duct is positioned in fluid communication with the nozzle duct, and has at least one portion with a cross-sectional shape geometrically similar to the second cross-sectional shape. A first mixing device is positioned proximate to the first axial position to mix fan flow in the fan flow duct portion with core flow in the core flow duct portion, and a second mixing device is positioned downstream of the first mixing device to mix the fan flow and the core flow with flow through the ejector duct, and direct the combined flow generally along the nozzle flow axis. A representative design technique can include selecting an axial position for, and tailoring the shape of, the second mixing device, such as, their spanwise spacings, to enhance flow characteristics of interest, e.g., identified via computational fluid dynamic techniques, that may appear at (e.g., only at) a downstream position.

Dissimilarly shaped aircraft nozzles with tandem mixing devices, and associated systems and methods are disclosed. An ejector nozzle in a representative embodiment includes a nozzle duct having a nozzle flow axis, a first axial position and a second axial position. The nozzle duct has a first cross-sectional shape at the first axial position, and a second cross-sectional shape at the second axial position, with the second shape being geometrically non-similar to the first shape. The nozzle further includes a fan flow duct portion and a core flow duct portion, both upstream of the first axial position. An ejector duct is positioned in fluid communication with the nozzle duct, and has at least one portion with a cross-sectional shape geometrically similar to the second cross-sectional shape. A first mixing device is positioned proximate to the first axial position to mix fan flow in the fan flow duct portion with core flow in the core flow duct portion, and a second mixing device is positioned downstream of the first mixing device to mix the fan flow and the core flow with flow through the ejector duct, and direct the combined flow generally along the nozzle flow axis. A representative design technique can include selecting an axial position for, and tailoring the shape of, the second mixing device, such as, their spanwise spacings, to enhance flow characteristics of interest, e.g., identified via computational fluid dynamic techniques, that may appear at (e.g., only at) a downstream position.

A three-stream gas turbine engine with an embedded electric machine and methods of operating the same are disclosed. In one aspect, a three-stream engine includes an electric machine operatively coupled with a shaft of the engine. The three-stream engine also includes a core engine and a primary fan and a mid-fan positioned upstream of the core engine. The primary fan and the mid-fan are operatively coupled with the shaft. During operation, the three-stream engine defines a tip speed ratio being defined by a tip speed of a rotor of the electric machine to a tip speed of a mid-fan blade of the mid-fan. The tip speed ratio is defined as being equal to or greater than 0.2 and less than or equal to 1.0.

A variable area nozzle assembly for a gas turbine engine includes a fixed structure including a first fixed ring and a second fixed ring. The second fixed ring is spaced axially aft from the first fixed ring to define a first portion of an ejector passage therebetween. A nozzle defines an inner radial exhaust flow path surface. The nozzle includes a forward ejector door and an aft ejector door. The forward ejector door and the aft ejector door define a first surface portion of the inner radial exhaust flow path surface. Each of the forward ejector door and the aft ejector door are pivotable between respective closed positions and respective open positions. A translating ejector sleeve is mounted within the fixed structure and configured to axially translate within the fixed structure between a first axial position and a second axial position.

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.

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.

The invention relates to an exhaust case (15) for a turbomachine extending along a longitudinal axis (X), comprising: an annular shroud (23) having a wall (24) extending along the longitudinal axis (X) from a first flange (25), a plurality of openings (27) being provided through the wall (24); a plurality of mouths (28) each forming a channel (29) extending upstream to downstream between a respective inlet (30) and one of the openings (27), each mouth (28) having: a docking flange (31) at the inlet (30) having a radially inner edge (32) which is in contact with the first flange (25) of the annular shroud (23), a mouth wall (34) delimiting the channel (29) and comprising a radially inner wall portion (35) which is formed by a thickened section made on the wall (24) of the shroud (23).

The invention relates to an exhaust case (15) for a turbomachine extending along a longitudinal axis (X), comprising: an annular shroud (23) having a wall (24) extending along the longitudinal axis (X) from a first flange (25), a plurality of openings (27) being provided through the wall (24); a plurality of mouths (28) each forming a channel (29) extending upstream to downstream between a respective inlet (30) and one of the openings (27), each mouth (28) having: a docking flange (31) at the inlet (30) having a radially inner edge (32) which is in contact with the first flange (25) of the annular shroud (23), a mouth wall (34) delimiting the channel (29) and comprising a radially inner wall portion (35) which is formed by a thickened section made on the wall (24) of the shroud (23).

A propulsion system is provided. The propulsion system defines a radial direction and includes a rotating element; a stationary element; an inlet assembly defining an inlet positioned between the rotating element and the stationary element and positioned inward of the stationary element along the radial direction, the inlet assembly comprising an inlet duct located downstream of the inlet; and a ducted fan comprising a plurality of fan blades positioned at least partially in the inlet duct; wherein the inlet duct divides into a first duct and a second duct separate from the first duct, wherein the first duct is a core duct downstream of the ducted fan, wherein the second duct is a fan duct downstream of the ducted fan, and wherein the second duct includes an exhaust nozzle having a plurality of chevrons disposed at an aft end of the exhaust nozzle to define an exhaust outlet.

A propulsion system is provided. The propulsion system defines a radial direction and includes a rotating element; a stationary element; an inlet assembly defining an inlet positioned between the rotating element and the stationary element and positioned inward of the stationary element along the radial direction, the inlet assembly comprising an inlet duct located downstream of the inlet; and a ducted fan comprising a plurality of fan blades positioned at least partially in the inlet duct; wherein the inlet duct divides into a first duct and a second duct separate from the first duct, wherein the first duct is a core duct downstream of the ducted fan, wherein the second duct is a fan duct downstream of the ducted fan, and wherein the second duct includes an exhaust nozzle having a plurality of chevrons disposed at an aft end of the exhaust nozzle to define an exhaust outlet.