A gas turbine engine including: a tail cone; a low pressure compressor; a low pressure turbine; a low speed spool interconnecting the low pressure compressor and the low pressure turbine; and an electric generator located within the tail cone, the electric generator being operably connected to the low speed spool, wherein the electric generator includes a coolant cavity in thermal communication with one or more components of the electric generator; a structural support housing at least partially enclosing the electric generator, the structural support housing including a forward wall located on a forward end of the structural support housing, wherein the forward wall includes a first opening; a first coolant conveying tube extending through the first opening to fluidly connect to the coolant cavity; and a first electrical connector tube extending through the first opening within the first coolant conveying tube to electrically connect to the electric generator.

A gas turbine engine including: a tail cone; a low pressure compressor; a low pressure turbine; a low speed spool interconnecting the low pressure compressor and the low pressure turbine; and an electric generator located within the tail cone, the electric generator being operably connected to the low speed spool, wherein the electric generator includes a coolant cavity in thermal communication with one or more components of the electric generator; a structural support housing at least partially enclosing the electric generator, the structural support housing including a forward wall located on a forward end of the structural support housing, wherein the forward wall includes a first opening; a first coolant conveying tube extending through the first opening to fluidly connect to the coolant cavity; and a first electrical connector tube extending through the first opening within the first coolant conveying tube to electrically connect to the electric generator.

A gas turbine engine system and method of operating gas turbine engines are provided. The gas turbine engine assembly includes a gas turbine engine includes a power shaft configured to rotate about an axis of rotation. The gas turbine engine assembly also includes a first fan and a second fan coupled to the power shaft coaxially with the gas turbine engine. The gas turbine engine assembly also includes a first fan duct configured to direct a first stream of air to the first fan. The gas turbine engine assembly also includes a second fan duct configured to direct a second stream of air to the second fan. The gas turbine engine assembly also includes an exhaust duct configured to direct a stream of exhaust gases of the gas turbine engine in a direction of the axis of rotation.

A gas turbine engine system and method of operating gas turbine engines are provided. The gas turbine engine assembly includes a gas turbine engine includes a power shaft configured to rotate about an axis of rotation. The gas turbine engine assembly also includes a first fan and a second fan coupled to the power shaft coaxially with the gas turbine engine. The gas turbine engine assembly also includes a first fan duct configured to direct a first stream of air to the first fan. The gas turbine engine assembly also includes a second fan duct configured to direct a second stream of air to the second fan. The gas turbine engine assembly also includes an exhaust duct configured to direct a stream of exhaust gases of the gas turbine engine in a direction of the axis of rotation.

A gas turbine engine for an aircraft includes: an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor, wherein the engine core extends along a rotational axis, and has an engine core diameter perpendicular to the rotational axis; and a fan having a plurality of fan blades extending radially from the rotational axis, wherein the fan has a fan diameter perpendicular to the rotational axis, wherein a ratio of the engine core diameter to the fan diameter is between 1:1.7 and 1:2.2.

A gas turbine engine for an aircraft includes: an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor, wherein the engine core extends along a rotational axis, and has an engine core diameter perpendicular to the rotational axis; and a fan having a plurality of fan blades extending radially from the rotational axis, wherein the fan has a fan diameter perpendicular to the rotational axis, wherein a ratio of the engine core diameter to the fan diameter is between 1:1.7 and 1:2.2.

A highly efficient gas turbine engine is provided. The fan of the gas turbine engine is driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

A highly efficient gas turbine engine is provided. The fan of the gas turbine engine is driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

An after-fan system for an engine may comprise an after-fan turbine an electrical generator operationally coupled to the after-fan turbine, and an electric motor electrically coupled to the electrical generator. The electrical generator may be configured to generate an electrical current in response to rotation of the after-fan turbine. The electric motor may be configured to generate torque.

An after-fan system for an engine may comprise an after-fan turbine an electrical generator operationally coupled to the after-fan turbine, and an electric motor electrically coupled to the electrical generator. The electrical generator may be configured to generate an electrical current in response to rotation of the after-fan turbine. The electric motor may be configured to generate torque.