Abstract: A disclosed gas turbine engine includes a first electric motor assembly that provides a first drive input for driving fan blades about an axis. A geared architecture is driven by a turbine section and is coupled to the fan section to provide a second drive input for driving the fan blades. A second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure for controlling a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: A gas turbine engine includes a fan positioned at an engine central longitudinal axis, and a fan drive turbine located at the engine central longitudinal axis and configured to drive rotation of the fan. A gas generator is non-coaxial with the fan drive turbine and operably connected to the fan drive turbine such that exhaust from the gas generator drives rotation of the fan drive turbine. An auxiliary power core is located at the engine central longitudinal axis, and one or more bleed passages connect the gas generator and the auxiliary power core. The one or more bleed passages are configured to selectably combine a bleed airflow from the gas generator and an auxiliary core airflow at the auxiliary power core to direct the combined airflow to the fan drive turbine to increase output of the fan drive turbine.

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: An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.

Abstract: A method for active bi-directional control of an outer structure of a gas turbine engine comprises sending, by a controller, a first control signal to a power electronics for varying an electric current supplied to a heating element to cause the outer structure to move in a first radial direction, and sending, by the controller, a second control signal to a valve assembly for varying a cooling air flow supplied to the outer structure to cause the outer structure to move in a second radial direction. The first radial direction is opposite the second radial direction.

Abstract: A gas turbine engine includes a fan positioned at an engine central longitudinal axis, and a fan drive turbine located at the engine central longitudinal axis and configured to drive rotation of the fan. A gas generator is non-coaxial with the fan drive turbine and operably connected to the fan drive turbine such that exhaust from the gas generator drives rotation of the fan drive turbine. An auxiliary power core is located at the engine central longitudinal axis, and one or more bleed passages connect the gas generator and the auxiliary power core. The one or more bleed passages are configured to selectably combine a bleed airflow from the gas generator and an auxiliary core airflow at the auxiliary power core to direct the combined airflow to the fan drive turbine to increase output of the fan drive turbine.

Abstract: A gas turbine engine includes a turbine section located at an engine central longitudinal axis, a combustor configured to drive rotation of the turbine with combustion products, and a compressor section coupled to the turbine section at the engine central longitudinal axis and driven by the turbine section. An auxiliary compressor is located fluidly between the compressor section and the combustor such that an airflow exiting the compressor section is directed toward the auxiliary compressor. The auxiliary compressor is driven independently from the compressor section and is configured to output the airflow toward the combustor.

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: An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.

Abstract: A clearance control system for a gas turbine engine may include a rotor blade, an outer structure disposed radially outward from the rotor blade, a heating element, a hybrid electric power source, and a controller. The heating element is configured to cause the outer structure to be heated in response to electric current being supplied to the heating element. A gap between the rotor blade and the outer structure is at least one of increased, decreased, and maintained in response to the outer structure being heated. The hybrid electric power source is configured to supply the electric current to the heating element. The controller is configured to regulate the electric current being supplied to the heating element.

Abstract: An aircraft gas turbine engine system comprises first and second gas turbine engines. The first gas turbine engine has first and second spools. A first power linkage connects the second gas turbine engine to the first spool of the gas turbine engine, and a second power linkage connects the second gas turbine engine to the second spool of the first gas turbine engine.

Abstract: An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.

Abstract: A gas turbine engine includes a core flowpath for flowing a core stream, a second flowpath located radially outward from the core flowpath for flowing a second stream, and an auxiliary flowpath located radially outward from the second flowpath for flowing an auxiliary stream. A heat exchanging device is constructed and arranged to divert a portion of the second stream into the auxiliary flowpath. A turbine exhaust case is constructed and arranged to flow the auxiliary stream into the core flowpath for mixing with the core stream.

Abstract: A gas turbine engine according to an exemplary embodiment of this disclosure includes among other possible things, a fan section including a plurality of fan blades, a first electric motor assembly that provides a first drive input for driving the fan blades about an axis, a turbine section, and a geared architecture driven by the turbine section and coupled to the fan section to provide a second drive input for driving the fan blades, and second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure controls a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: A gas turbine engine according to an exemplary embodiment of this disclosure includes among other possible things, a fan section including a plurality of fan blades, a first electric motor assembly that provides a first drive input for driving the fan blades about an axis, a turbine section, and a geared architecture driven by the turbine section and coupled to the fan section to provide a second drive input for driving the fan blades, and second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure controls a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: An aspect includes a dirt mitigation system for a gas turbine engine. The dirt mitigation system includes a plurality of bleeds of the gas turbine engine and a control system configured to determine a particulate ingestion estimate indicative of dirt ingested in the gas turbine engine. The control system is further configured to determine one or more operating parameters of the gas turbine engine and alter a bleed control schedule of the gas turbine engine to purge at least a portion of the dirt ingested in the gas turbine engine through one or more of the bleeds of the gas turbine engine based on the particulate ingestion estimate and the one or more operating parameters.

Abstract: A clearance control system for a gas turbine engine may comprise a rotor blade, an outer structure disposed radially outward from the rotor blade, and a heating element configured to cause the outer structure to be heated in response to electric current being supplied to the heating element, wherein a gap between the rotor blade and the outer structure is at least one of increased, decreased, and maintained in response to the outer structure being heated.

Abstract: An aircraft gas turbine engine system comprises first and second gas turbine engines connected by an inter-engine gas path. The first gas turbine engine has a first spool with a first compressor section, and a second spool with a second compressor section downstream of and rotationally independent from the first compressor section. The second gas turbine engine is configured to provide power to at least one of the first and second spools of the first gas turbine engine. The inter-engine gas path is disposed to receive gas flow bled from a bleed location in the first gas turbine engine downstream of the first compressor section, and to supply this gas flow to an inlet of the second gas turbine engine.

Abstract: A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.

Abstract: A clearance control system for a gas turbine engine may include a rotor blade, an outer structure disposed radially outward from the rotor blade, a heating element, a hybrid electric power source, and a controller. The heating element is configured to cause the outer structure to be heated in response to electric current being supplied to the heating element. A gap between the rotor blade and the outer structure is at least one of increased, decreased, and maintained in response to the outer structure being heated. The hybrid electric power source is configured to supply the electric current to the heating element. The controller is configured to regulate the electric current being supplied to the heating element.