Abstract: A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool, a high speed spool, and a combustor; a lubrication circuit comprising a bearing compartment, a supply pump, and a scavenger pump; an electric motor configured to augment rotational power of the low speed spool or the high speed spool; and a controller operable to: control the electric motor based upon a pressure differential between an interior of the bearing compartment and an exterior of the bearing compartment and to drive rotation of the low speed spool and/or the high speed spool via the electric motor responsive to a thrust command while fuel flow to the combustor is inhibited.

Abstract: A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool, a high speed spool, and a combustor; a lubrication circuit comprising a bearing compartment, a supply pump, and a scavenger pump; an electric motor configured to augment rotational power of the low speed spool or the high speed spool; and a controller operable to: control the electric motor based upon a pressure differential between an interior of the bearing compartment and an exterior of the bearing compartment and to drive rotation of the low speed spool and/or the high speed spool via the electric motor responsive to a thrust command while fuel flow to the combustor is inhibited.

Abstract: A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool, a high speed spool, and a combustor; a lubrication circuit comprising a bearing compartment, a supply pump, and a scavenger pump; an electric motor configured to augment rotational power of the low speed spool or the high speed spool; and a controller operable to: control the electric motor based upon a pressure differential between an interior of the bearing compartment and an exterior of the bearing compartment and to drive rotation of the low speed spool and/or the high speed spool via the electric motor responsive to a thrust command while fuel flow to the combustor is inhibited.

Abstract: Oil lubrication systems for use on gas turbine engines are described. The systems include a conduit and an air/oil separator connected to and arranged along the conduit. The air/oil separator comprises includes a housing and a semi-permeable divider within the housing, the semi-permeable divider being permeable to air but not oil. The semi-permeable divider separates a first flow path of an air/oil mixture and a second flow path of low pressure such that air from the air/oil mixture passes through the semi-permeable divider and is removed from the air/oil mixture, and wherein an air-to-oil ratio is less at the second end of the first flow path as compared to the air-to-oil ratio at the first end of the first flow path.

Abstract: A gas turbine engine includes a turbine and a compressor in rotational communication with the turbine via a shaft. The shaft is rotatable about a longitudinal centerline and includes a first axial end and a second axial end opposite the first axial end. The gas turbine engine further includes a first bearing compartment including a first compartment casing detachably mounted axially outside the compressor and the turbine. The first bearing compartment is in contact with the first axial end of the shaft and includes a first bearing which rotatably supports the shaft. The first bearing compartment is self-contained such that an internal lubrication system of the first bearing compartment is fluidally isolated from a remainder of the gas turbine engine outside the first bearing compartment.

Abstract: An assembly is provided that includes a shaft, a bearing, a stator seal element, a rotor seal element and a shield. The shaft extends along an axis. The bearing supports the shaft and receives lubrication fluid. The stator seal element circumscribes the shaft. The rotor seal element is mounted on the shaft axially between the bearing and the stator seal element. The rotor seal element forms a seal with the stator seal element. The shield substantially prevents the lubrication fluid from traveling axially away from the bearing onto the rotor seal element.

Abstract: A lubrication system is disclosed. The lubrication system may be used in conjunction with a gas turbine engine for generating power or lift. The lubrication system utilized a flow scheduling valve which reduces lubricant flow to at least one component based on an engine load. The lubrication system may further include a main pump which may be regulated by an engine speed. Thus, a lubrication system which provides a lubricant to engine components based on the load and speed of the engine is possible. The system may improve efficiency of the engine by reducing the power previously spent in churning excess lubricant by at least one engine component as well as reducing the energy used by a lubricant cooler in cooling the excess lubricant. The lubricant cooler size may also be minimized to reduce weight and air drag due to the reduced lubricant flow.

Abstract: A gas turbine engine includes a turbine and a compressor in rotational communication with the turbine via a shaft. The shaft is rotatable about a longitudinal centerline and includes a first axial end and a second axial end opposite the first axial end. The gas turbine engine further includes a first bearing compartment including a first compartment casing detachably mounted axially outside the compressor and the turbine. The first bearing compartment is in contact with the first axial end of the shaft and includes a first bearing which rotatably supports the shaft. The first bearing compartment is self-contained such that an internal lubrication system of the first bearing compartment is fluidally isolated from a remainder of the gas turbine engine outside the first bearing compartment.

Abstract: Oil lubrication systems for use on gas turbine engines are described. The systems include a conduit and an air/oil separator connected to and arranged along the conduit. The air/oil separator comprises includes a housing and a semi-permeable divider within the housing, the semi-permeable divider being permeable to air but not oil. The semi-permeable divider separates a first flow path of an air/oil mixture and a second flow path of low pressure such that air from the air/oil mixture passes through the semi-permeable divider and is removed from the air/oil mixture, and wherein an air-to-oil ratio is less at the second end of the first flow path as compared to the air-to-oil ratio at the first end of the first flow path.

Abstract: According to an aspect, a method includes predicting, by a processor, a projected oil-wetted metal temperature in a lubrication system of a gas turbine engine at shutdown based on one or more thermal models prior to shutdown of the gas turbine engine. The processor determines a coking index based on the projected oil-wetted metal temperature and a coking limit threshold associated with one or more engine components. An oil coking mitigation action is triggered as a shutdown management event of the gas turbine engine based on the coking index.

Abstract: A gas turbine engine according to an example of the present disclosure includes a shaft rotatable about an axis, a bearing disposed about the shaft and within a bearing compartment, and a seal assembly positioned to seal the bearing compartment. The seal assembly includes a fixed seal and a seal runner rotatable with the shaft. The first axial face and a second axial face axially opposite the first axial face with respect to the axis. The first axial face includes a first surface rotatable against the seal, and the second axial face includes a trough portion. A second surface is angled relative to a radial baseline plane defined perpendicular to the axis, and a dam between the trough portion and the second surface. An oil source is positioned to provide oil into the trough portion.

Abstract: A lubrication system for use with a gas turbine engine includes a first reservoir for containing a lubricant. The first reservoir includes a first discharge passage through which the lubricant is flowable in a first direction. A second reservoir contains the lubricant. The second reservoir includes a second discharge passage through which the lubricant is flowable in a second direction. The first direction is generally opposite to the second direction. A first pump pumps the lubricant from the first reservoir. A second pump pumps the lubricant from the second reservoir. A manifold distributes the lubricant to a component. The lubricant from the first pump and the second pump flows into the manifold and exits the manifold through a manifold discharge.

Abstract: An engine health monitoring system includes an engine component having a sensor system configured to monitor at least one parameter of the component. An autonomous monitoring system is coupled to the sensor system and is configured to receive and store the at least one monitored parameter while an engine controller is unpowered. The engine controller is communicatively coupled to the autonomous monitoring system.

Abstract: A fluid damping structure is provided that includes a damper ring. The damper ring includes an annular body a plurality of fluid check valves, and at least one fluid stop. The annular body extends circumferentially around an axial centerline, and is defined by a first end surface, a second end surface, an outer radial surface, and an inner radial surface. The outer radial surface and the inner radial surface extend axially from the first end surface toward the second end surface. The body includes one or more check valve passages. Each check valve passage extends axially from an open end disposed at the first end surface inwardly toward the second end surface, and is disposed between the inner radial surface and the outer radial surface. An inlet aperture extends between each check valve passage and the outer radial surface, and an outlet aperture extends between each check valve passage and the inner radial surface. Each fluid check valve is disposed in a check valve passage.

Abstract: A gas turbine engine according to an example of the present disclosure includes a shaft rotatable about an axis, a bearing disposed about the shaft and within a bearing compartment, and a seal assembly positioned to seal the bearing compartment. The seal assembly includes a fixed seal and a seal runner rotatable with the shaft. The first axial face and a second axial face axially opposite the first axial face with respect to the axis. The first axial face includes a first surface rotatable against the seal, and the second axial face includes a trough portion. A second surface is angled relative to a radial baseline plane defined perpendicular to the axis, and a dam between the trough portion and the second surface. An oil source is positioned to provide oil into the trough portion.

Abstract: A system for a turbine engine includes a turbine engine component, a lubricant collection device and a plurality of lubricant circuits. The lubricant collection device is fluidly coupled with the turbine engine component. The lubricant circuits are fluidly coupled between the lubricant collection device and the turbine engine component. The lubricant circuits include a first circuit and a second circuit configured in parallel with the first circuit. Each of the lubricant circuits includes a lubricant pump. The first and the second circuits receive lubricant from the lubricant collection device, and direct the received lubricant to the turbine engine component.

Abstract: Aspects of the disclosure are directed to a system associated with an engine, comprising: a bearing compartment, a scavenge line coupled to the bearing compartment at a first end of the scavenge line that receives a fluid via the first end of the scavenge line, a fluid pump coupled to the scavenge line at a second end of the scavenge line to receive the fluid, and a flow control valve having a variable flow area and disposed in the scavenge line to control flow of the fluid in the scavenge line and the fluid pump.

Abstract: An assembly is provided that includes a shaft, a bearing, a stator seal element, a rotor seal element and a shield. The shaft extends along an axis. The bearing supports the shaft and receives lubrication fluid. The stator seal element circumscribes the shaft. The rotor seal element is mounted on the shaft axially between the bearing and the stator seal element. The rotor seal element forms a seal with the stator seal element. The shield substantially prevents the lubrication fluid from traveling axially away from the bearing onto the rotor seal element.

Abstract: An assembly is provided that includes a shaft, a bearing, a stator seal element, a rotor seal element and a shield. The shaft extends along an axis. The bearing supports the shaft and receives lubrication fluid. The stator seal element circumscribes the shaft. The rotor seal element is mounted on the shaft axially between the bearing and the stator seal element. The rotor seal element forms a seal with the stator seal element. The shield substantially prevents the lubrication fluid from traveling axially away from the bearing onto the rotor seal element.

Abstract: A disclosed lubrication system for a gas turbine engine includes a primary passage defining a flow path for lubricant to a gas turbine engine and a bypass passage defining a flow path for lubricant around the gas turbine engine. The lubrication system further includes a primary lubrication pump including a reduced total flow capacity of lubricant with a reduced bypass lubricant flow relative to the total overall flow capacity.