Abstract: A gas turbine engine includes a core section including a compressor, a main combustor, and a main turbine. Combustion products from the main combustor drive rotation of the turbine and the compressor. A power turbine is fluidly connected to the main turbine and driven by exhaust from the main turbine. The gas turbine engine further includes a fan section having a fan rotor located fluidly upstream of the core section. The power turbine is operably connected to the fan rotor to drive rotation of the fan rotor via rotation of the power turbine. The gas turbine engine includes a bleed arrangement having one or more bleed passages configured to divert a bleed airflow from the compressor around the main combustor and main turbine, and reintroduce the bleed airflow into the power turbine.

Abstract: A method of distributing power within a gas turbine engine is disclosed. In various embodiments, the method includes driving a high pressure turbine having a first stage and a second stage with an exhaust stream from a combustor, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; driving a high pressure compressor connected to a high pressure compressor spool via a differential system, the differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear assembly connected to the high pressure compressor spool; and selectively applying an auxiliary input power into at least one of the high pressure compressor spool and the high pressure turbine.

Abstract: Gas turbine engines and rotor arms thereof are described. The gas turbine engines include a first disk, a second disk, and a rotor arm arranged between and connecting the first disk to the second disk, wherein a cavity is defined at least between the rotor arm and the first disk. The rotor arm includes a radial portion having an inner diameter end and an outer diameter end, an axial portion having a first end and a second end, wherein the first end of the axial portion is connected to the outer diameter end of the radial portion, at least one entrance flow path defined within the radial portion extending from the inner diameter end to the outer diameter end, and at least one exit aperture arranged proximate the second end of the axial portion.

Abstract: A gas turbine engine is disclosed. In various embodiments, the gas turbine engine includes a high pressure turbine having a first stage and a second stage, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; a high pressure compressor connected to a high pressure compressor spool; and a differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear connected to the high pressure compressor spool.

Abstract: A method of distributing power within a gas turbine engine is disclosed. In various embodiments, the method includes driving a high pressure turbine having a first stage and a second stage with an exhaust stream from a combustor, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; driving a high pressure compressor connected to a high pressure compressor spool via a differential system, the differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear assembly connected to the high pressure compressor spool; and selectively applying an auxiliary input power into at least one of the high pressure compressor spool and the high pressure turbine.

Abstract: A turboshaft engine includes a core section extending between an inlet and an outlet of the turboshaft engine. The core section includes a compressor, a main combustor, and a main turbine, such that combustion products from the main combustor drives rotation of the turbine and the compressor. A power turbine is fluidly connected to the main turbine and driven by exhaust from the main turbine. A primary bypass is fluidly connected to the inlet and the outlet. The primary bypass directs a portion of an airflow entering the inlet around the core section to the outlet. A secondary bypass is located in the core section and is configured to divert a portion of a core airflow of the core section around the main combustor and the main turbine to the power turbine.

Abstract: A cooling system for a component of a gas turbine engine includes a first airflow passage configured to direct a first airflow to a mixing chamber and a second airflow passage to configured direct a second airflow to the mixing chamber, the second airflow having a higher temperature than the first airflow, and a cooling airflow passage to direct a cooling airflow from the mixing chamber to the component, the cooling airflow comprising the first airflow and the second airflow. The airflow passages are configured and sized to allow an amount of cooling airflow for unrestricted engine operation. When the first airflow passage is disabled, the second airflow passage and cooling airflow passage are configured and sized to allow an amount of cooling airflow which is adequate to permit continued safe engine operation restricted to within only a portion of its normal parameters and operating envelope.

Abstract: A shaft and sleeve assembly of a gas turbine engine includes an outer shaft extending about an engine central longitudinal axis and having a radially inner shaft surface. The radially inner shaft surface has a shaft groove define therein. A sleeve is located radially inboard of the radially inner shaft surface. The sleeve includes a sleeve groove defined in a radially outer sleeve surface. The sleeve groove is formed at an axial location between a first axial end and a second axial end of the sleeve. A retaining element is installed in the shaft groove and the sleeve groove to retain the sleeve relative to the outer shaft. The sleeve includes one or more sleeve openings formed therein, and the sleeve groove is aligned with the one or more sleeve openings.

Abstract: A hybrid electric gas turbine engine includes a fan section having a fan, a turbine section having a turbine drivably connected to the fan through a main shaft that extends along a central longitudinal axis, a gas generating core extending along a first axis that is radially offset from the central longitudinal axis, a first electric motor drivably connected to the main shaft, wherein the electric motor is colinear with the main shaft, and an electric compressor extending along a second axis that is radially offset from the central longitudinal axis, the electric compressor in fluid communication with the second turbine section.

Abstract: A shaft and sleeve assembly of a gas turbine engine includes an outer shaft extending about an engine central longitudinal axis and having a radially inner shaft surface. The radially inner shaft surface has a shaft groove define therein. A sleeve is located radially inboard of the radially inner shaft surface. The sleeve includes a sleeve groove defined in a radially outer sleeve surface. The sleeve groove is formed at an axial location between a first axial end and a second axial end of the sleeve. A retaining element is installed in the shaft groove and the sleeve groove to retain the sleeve relative to the outer shaft. The sleeve includes one or more sleeve openings formed therein, and the sleeve groove is aligned with the one or more sleeve openings.

Abstract: A bearing assembly of a gas turbine engine includes a bearing inner race, a bearing outer race located radially outboard of the bearing inner race and a plurality of bearing elements located between the bearing inner race and the bearing outer race. A centering spring is operably connected to and supports the bearing outer race. The centering spring is an annular structure including a base portion, a tip portion, and a plurality of beams extending axially between the base portion and the tip portion.

Abstract: A section for a gas turbine engine according to an example of the present disclosure includes, among other things, a rotor including a row of blades extending in a radial direction outwardly from a hub. The row of blades deliver flow to a bypass flow path, an intermediate flow path, and a core flow path. A first case surrounds the row of blades to establish the bypass flow path. A first flow splitter divides flow between the bypass flow path and a second duct. A row of guide vanes extends in the radial direction across the bypass flow path. A second flow splitter radially inboard of the first flow splitter divides flow from the second duct between the intermediate flow path and the core flow path. A bypass port interconnects the intermediate and bypass flow paths. A method of operation for a gas turbine engine is also disclosed.

Abstract: A turbine engine includes a core engine including a first spool and a second spool rotatable about a main engine longitudinal axis, a boost spool powered by a secondary drive system, and an accessory gearbox coupled to the core engine and the boost spool. A differential gear system is coupled between the core engine, the boost spool and the accessory gearbox for distributing power between the boost spool, the core engine and the accessory gearbox.

Abstract: A gas turbine engine includes a first spool, a second spool, a primary combustor, and a diffuser. The first spool includes a first compressor rotationally driven by a first turbine via a first shaft. The second spool includes a second compressor driven by a second turbine via a second shaft. The first compressor, the diffuser, and the primary combustor are arranged in series to provide a compressed airflow discharged from the first compressor to the primary combustor via the diffuser, which includes walls that diverge towards the primary combustor. The second compressor is fluidly coupled to the diffuser to receive at least a portion of the compressed airflow from the diffuser. The second turbine is fluidly coupled to the diffuser to discharge an expanded airflow to the diffuser.

Abstract: A hybrid electric gas turbine engine includes a fan section having a fan, a turbine section having a turbine drivably connected to the fan through a main shaft that extends along a central longitudinal axis, a gas generating core extending along a first axis that is radially offset from the central longitudinal axis, a first electric motor drivably connected to the main shaft, wherein the electric motor is colinear with the main shaft, and an electric compressor extending along a second axis that is radially offset from the central longitudinal axis, the electric compressor in fluid communication with the second turbine section.

Abstract: A hybrid electric gas turbine engine includes a fan section having a fan, a turbine section having a turbine drivably connected to the fan through a main shaft that extends along a central longitudinal axis, a gas generating core extending along a first axis that is radially offset from the central longitudinal axis, a first electric motor drivably connected to the main shaft, wherein the electric motor is colinear with the main shaft, and an electric compressor extending along a second axis that is radially offset from the central longitudinal axis, the electric compressor in fluid communication with the second turbine section.

Abstract: A gas turbine engine is disclosed. In various embodiments, the gas turbine engine includes a low speed spool; a first compressor, a turbine and a generator rotationally coupled via the low speed spool; a high speed spool; and a second compressor and a motor rotationally coupled via the high speed spool.

Abstract: A gas turbine engine is disclosed. In various embodiments, the gas turbine engine includes a high pressure turbine having a first stage and a second stage, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; a high pressure compressor connected to a high pressure compressor spool; and a differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear connected to the high pressure compressor spool.

Abstract: A method of distributing power within a gas turbine engine is disclosed. In various embodiments, the method includes driving a high pressure turbine having a first stage and a second stage with an exhaust stream from a combustor, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; driving a high pressure compressor connected to a high pressure compressor spool via a differential system, the differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear assembly connected to the high pressure compressor spool; and selectively applying an auxiliary input power into at least one of the high pressure compressor spool and the high pressure turbine.

Abstract: A gas turbine engine includes a compressor section, a combustor fluidly connected to the compressor section via a primary flowpath and a turbine section fluidly connected to the combustor via the primary flowpath. Also included is a cascading cooling system having a first inlet connected to a first compressor bleed, a second inlet connected to a second compressor bleed downstream of the first compressor bleed, and a third inlet connected to a third compressor bleed downstream of the second compressor bleed. The cascading cooling system includes at least one heat exchanger configured to incrementally generate cooling air for at least one of an aft compressor stage and a foremost turbine stage relative to fluid flow through the turbine section.