Abstract: A system includes a thermal engine operatively connected to drive a propeller. An electric motor is operatively connected to the thermal engine to drive the propeller together with the thermal engine. An external input system is configured to accept input and output a thrust command. A protection function module is configured to enforce limits on the thermal engine, electric motor, and propeller. A low select module is operatively connected to receive input from the external input system and form the protection function module and to output the lower of input from the protection function module and external input system to the thermal engine, the electric motor, and the propeller.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine that has high efficiency provides low noise, in particular from the fan and the turbine that drives the fan. Values are defined for a noise parameter NP that results in a gas turbine engine having reduced combined fan and turbine noise.

Abstract: An aircraft engine has a high pressure spool including a high pressure turbine drivingly connected to a high pressure compressor. A low pressure spool including a low pressure compressor is fluidly connected to the high pressure compressor. A low pressure turbine is drivingly connected to the low pressure compressor to drive the low pressure compressor. A load is drivingly connected to the low pressure turbine, the load consisting of one of a propeller and a helicopter rotor. A method of creating classes of an aircraft engine from an engine platform is disclosed.

Abstract: A booster splitter for a gas turbine engine and a method of additively manufacturing the booster splitter are provided. The booster splitter includes an annular inner wall defining a radially outer boundary of a compressor flow path defined through a compressor section of the gas turbine engine, an annular outer wall spaced apart from the annular inner wall along the radial direction, the annular outer wall adjacent to the annular inner wall at a forward end, the forward end defining an inlet to the compressor flow path, an annular bulkhead spanning between the annular inner wall and the annular outer wall substantially along the radial direction, the bulkhead defining an inlet port, and a passageway defined within the annular outer wall, the passageway extending from the inlet port, into the bulkhead, radially outward to the outer wall, and through the annular outer wall towards the inlet defined by the forward end.

Abstract: A method for operating a hybrid electric propulsion system of an aircraft, the hybrid electric propulsion system comprising a turbomachine, an electric machine coupled to the turbomachine, and a propulsor coupled to the turbomachine, the method comprising: operating the turbomachine to drive the propulsor; receiving data indicative of a failure condition of the hybrid electric propulsion system; and extracting power from the turbomachine using the electric machine to slow down one or more rotating components of the turbomachine in response to receiving the data indicative of the failure condition.

Abstract: Technology for operating an engine smoothly is provided. In an aircraft propulsion system, a controller causes at least a first engine among the plurality of engines to be stopped and causes a second engine, which has not been stopped, to be operated when an aircraft is flying in a prescribed flight mode and causes the first engine to be operated and causes the second engine to be stopped when a detector detects that the temperature related to the first engine is less than or equal to a first prescribed temperature.

Abstract: A method for execution by a computing entity includes interpreting a fluid flow response from fluid flow sensors to produce a piston velocity and a piston position of a piston associated with a head unit device. The head unit device includes a chamber filled with a shear thickening fluid (STF) and a variable partition positioned within the chamber between the piston and a closed end of the chamber to dynamically affect volume of the chamber based on activation of the variable partition. The method further includes determining a shear force based on the piston velocity and the piston position. The method further includes determining a desired response for the STF based on the shear force, the piston velocity, and the piston position. The method further includes activating the variable partition using the desired response for the STF to adjust the volume of the chamber.

Abstract: An exemplary aircraft includes a turbine engine having a gas generator spool and a power spool, the power spool operational to drive a rotor, a first generator coupled to the gas generator spool, and a controller operable to increase a load on the gas generator spool when the gas generator spool is on a speed limit thereby increasing a speed limit margin in order to increase power available from the turbine engine.

Abstract: A combustor liner for a combustor of a gas turbine includes an outer liner and an inner liner. At least one of the outer liner and the inner liner has an upstream liner portion and a downstream liner portion with an annular gap therebetween. At least one dilution flow assembly is arranged to bridge across the annular gap. The at least one dilution flow assembly includes an upstream liner panel and a downstream liner panel with a dilution opening provided between the upstream liner panel and the downstream liner panel, and a plurality of dilution fence members arranged within the dilution opening and extending into a combustion chamber. The plurality of dilution fence members are arranged in successive arrangement in a circumferential direction and are arranged such that successive dilution fence members are alternatingly offset in an axial direction.

Abstract: A hybrid electric propulsion system includes a gas turbine engine having at least one compressor section and at least one turbine section operably coupled to a shaft. The hybrid electric propulsion system includes an electric motor configured to augment rotational power of the shaft of the gas turbine engine. A controller is operable to determine an estimate of hybrid electric propulsion system parameters based on a composite system model and sensor data, determine a model predictive control state and a prediction based on the hybrid electric propulsion system parameters and the composite system model, determine a model predictive control optimization for a plurality of hybrid electric system control effectors based on the model predictive control state and the prediction using a plurality of reduced-order partitions of the composite system model, and actuate the hybrid electric system control effectors based on the model predictive control optimization.

Abstract: The disclosure is towards an inlet cowl for a turbine engine including a surface defining an inlet with a flow path and a method towards controlling the airflow in the flow path. The inlet cowl further includes an inlet lip and inner and outer barrels. The inlet lip confronts the inner barrel at a junction defining a gap.

Abstract: A turbofan engine has a fan portion in fluid communication with a core stream and a bypass stream of air separated by splitters disposed both upstream and downstream of the fan portion. A blade splitter (shroud) on the fan partially spans the fan blade thus separating the core and bypass streams downstream while leaving a gap upstream for communication between the flows. The communication gap expands the operational range of the fan over fans without the communication gap.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine that has high efficiency provides low noise, in particular from the fan and the turbine that drives the fan. Values are defined for a noise parameter NP that results in a gas turbine engine having reduced combined fan and turbine noise.

Abstract: A gas turbine engine includes a compressor section, a combustor section, and a turbine section operably coupled to the compressor section. A primary flow path is defined through the compressor section, the combustor section, and the turbine section. An engine case surrounds the compressor section, the combustor section, and the turbine section. The gas turbine engine also includes a means for providing an active variable cooling flow through a bypass duct external to the engine case to a secondary flow cavity of the turbine section.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: A loading/unloading method for a gas turbine system is disclosed. The gas turbine system includes a combustion section featuring a primary combustion stage with a first plurality of fuel nozzles and a downstream, secondary combustion stage with a second plurality of fuel nozzles. For loading, the method progresses through each of a plurality of progressive combustion modes that sequentially activate a higher number of at least one of the first or second plurality of fuel nozzles; and for unloading, the method progresses through each of a plurality of progressive combustion modes that sequentially activate a lower number of at least one of the first or second plurality of fuel nozzles. During each combustion mode, regardless of whether loading or unloading, a primary combustion stage exit temperature of a combustion gas flow is controlled to be within a predefined target range corresponding to the respective combustion mode.

Abstract: Systems and methods for adjusting a variable geometry mechanism of an engine are described herein. An engine control request indicative of a desired output power for the engine is monitored. A rate of change of the engine control request is determined. The rate of change is compared to a threshold. Responsive to determining that the rate of change is beyond the threshold, a transient bias map is applied to a steady-state schedule to generate a variable geometry mechanism request indicative of a target position for the variable geometry mechanism. The variable geometry mechanism is adjusted toward the target position according to the variable geometry mechanism request.

Abstract: A lightweight lift system for VTOL/VSTOL operation running in parallel with an existing turbine. This system distributes LP power by switching compressor flow and fuel proportionally over to the lift turbine module. As forward thrust is demanded, some of the power is transitioned back to the flight LP turbine, which can drive a variable propeller, fan or can supply jet thrust. As flight motion occurs, the power to the lift fan can be reduced to zero and lift closed off.

Abstract: A gas turbine engine includes a fan bypass ratio greater than 12. A speed reduction device includes a gear ratio of at least 2.6. A turbine section includes a transition duct that is located between a high pressure turbine and a low pressure turbine and includes fewer support struts than vanes in a first vane row of the low pressure turbine.

Abstract: A lubrication system may comprise a shaft including a shaft gear, a pump configured to supply a flow of lubricant to a component benefiting from lubrication and an input gear train coupled to the shaft gear and configured to drive the gear pump with a unidirectional rotation in response to a forward rotation and an reverse rotation of the shaft gear. The input gear grain may comprise a primary gear coupled to a common shaft. The input gear train may further comprise a forward shaft and a forward gear about the common shaft, wherein the forward gear is coupled to the forward shaft.