Apparatuses and systems are provided herein for unducted propulsion systems. The system includes an aft housing for low drag for high subsonic sustained flight. A plurality of blades are affixed to the aft housing, wherein the housing defines a flowpath curve extending from the axial extent of the aft blade root to the aft end of the aft housing. The flowpath curve is described by an axial direction parallel to an axis of rotation and a radius from the axis of rotation. The flowpath curve includes first point having a first radius where the radius reaches a maximum aft of the aft blade root and a second point forward of the first point having a second radius where the radius stops decreasing. The ratio of the first radius to the second radius is greater than or equal to 1.081.

Apparatuses and systems are provided herein for unducted propulsion systems. The system includes an aft housing for low drag for high subsonic sustained flight. A plurality of blades are affixed to the aft housing, wherein the housing defines a flowpath curve extending from the axial extent of the aft blade root to the aft end of the aft housing. The flowpath curve is described by an axial direction parallel to an axis of rotation and a radius from the axis of rotation. The flowpath curve includes first point having a first radius where the radius reaches a maximum aft of the aft blade root and a second point forward of the first point having a second radius where the radius stops decreasing. The ratio of the first radius to the second radius is greater than or equal to 1.081.

A damper seal for a turbomachine includes an annular body having an inner circumferential surface and an outer circumferential surface separated by a thickness. As such, the inner circumferential surface may define a plurality of cavities arranged into a plurality of circumferential rows and at least one partition positioned between at least two of the plurality of cavities. In addition, the inner circumferential surface may further define at least one plenum arranged between two of the plurality of circumferential rows.

A gas turbine engine which includes an outer casing; a central longitudinal hollow shaft with a forward air inlet; a three stage rotating superconducting electric bypass fan with front and rear fan blades and a diffuser blade interposed between said front and rear fan blades wherein the diffuser blade rotates in an opposite direction to the front and rear fan blades; a multiple stage superconducting axial compressor positioned aft of the three stage rotating superconducting electric bypass fan; a multiple stage superconducting electric turbine core positioned aft of the multiple stage variable speed superconducting axial compressor, whereby the electric power from the multiple stage superconducting electric turbine core powers the three stage superconducting electric bypass fan and the multiple stage superconducting axial compressor.

A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and an overall engine efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include a low-pressure turbine. The gearbox includes an input and an output. The input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0. The overall engine efficiency rating is within a range of 0.57-8.0.

A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and an overall engine efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include a low-pressure turbine. The gearbox includes an input and an output. The input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0. The overall engine efficiency rating is within a range of 0.57-8.0.

Counter-rotating turbine of a turbomachine extending about an axis of rotation and comprising an inner rotor having 5 at least one inner moving blade supported in rotation by a first shaft, an outer rotor rotating in an opposite direction to the inner rotor, and comprising at least one outer moving blade supported in rotation by a second shaft coaxial with the first shaft, the first 10 and second shafts extending axially from upstream to downstream of the turbine, the first shaft being guided in rotation by a first bearing disposed between the first shaft and an upstream casing of the turbine, and the second shaft being guided in rotation by a second bearing disposed between the second 15 shaft and said upstream casing of the turbine, the first bearing and the second bearing being disposed upstream of a first stage of the inner rotor.

Counter-rotating turbine of a turbomachine extending about an axis of rotation and comprising an inner rotor having 5 at least one inner moving blade supported in rotation by a first shaft, an outer rotor rotating in an opposite direction to the inner rotor, and comprising at least one outer moving blade supported in rotation by a second shaft coaxial with the first shaft, the first 10 and second shafts extending axially from upstream to downstream of the turbine, the first shaft being guided in rotation by a first bearing disposed between the first shaft and an upstream casing of the turbine, and the second shaft being guided in rotation by a second bearing disposed between the second 15 shaft and said upstream casing of the turbine, the first bearing and the second bearing being disposed upstream of a first stage of the inner rotor.

A turbo engine includes a system for changing a pitch of blades of a propeller, the system including an annular fluid cylinder with a linear drive and a link mechanism linking the cylinder to the blades of the propeller to change an orientation of the propeller. The annular cylinder of the system can be rigidly mounted on a fixed housing supporting the propeller and internal to the propeller, unlike the blades mounted in an external rotating hub of the propeller, and the link mechanism includes a displacement transfer bearing fixed, on one side, to the mobile part of the cylinder and cooperating, on the other side, with a mechanism linking to the blades of the rotating hub of the propeller.

A turbo engine includes a system for changing a pitch of blades of a propeller, the system including an annular fluid cylinder with a linear drive and a link mechanism linking the cylinder to the blades of the propeller to change an orientation of the propeller. The annular cylinder of the system can be rigidly mounted on a fixed housing supporting the propeller and internal to the propeller, unlike the blades mounted in an external rotating hub of the propeller, and the link mechanism includes a displacement transfer bearing fixed, on one side, to the mobile part of the cylinder and cooperating, on the other side, with a mechanism linking to the blades of the rotating hub of the propeller.