Gas turbine engine with microchannel cooled electric device

1. A gas turbine engine for use in an aircraft, the engine comprising

a low pressure spool including a fan arranged at a forward end of the engine, a low pressure turbine rotor arranged at an aft end of the engine, a low pressure drive shaft extending along an axis and rotationally coupling the fan to receive driven rotation from the low pressure turbine rotor,

a high pressure spool including a compressor rotor, a high pressure turbine rotor, and a high pressure drive shaft extending along the axis and rotationally coupling the compressor rotor to receive driven rotation from the high pressure turbine rotor, and

an electric device including a stator having an annular core, a rotor rotationally coupled to the low pressure drive shaft and disposed about the stator in electromagnetic communication, and a microchannel cooling system arranged radially inward of the stator in thermal communication with the annular core to pass coolant for removing heat from the stator, the microchannel cooling system including a housing and a network of micropassageways within the housing, the housing abutting a radially inner side of the stator,

wherein the network of micropassageways includes a first plurality of micropassageways that extend longitudinally parallel to the axis and that are spaced apart circumferentially and a second plurality of micropassageways that extend circumferentially relative to the axis and that are spaced apart axially such that the coolant flowing though the microchannel cooling system primarily only flows axially parallel with the axis and circumferentially relative to the axis.

2. The gas turbine engine of claim 1 , wherein the micropassageways include inlet passageways for receiving coolant and outlet passageways for discharging heated coolant.

3. The gas turbine engine of claim 2 , wherein each inlet passageway is connected with at least one of the outlet passageways by at least one transfer section to pass coolant in thermal communication with the annular core.

4. The gas turbine engine of claim 3 , wherein the at least one transfer section has a cross-sectional area that is smaller than a cross-sectional area of the inlet passageways and the outlet passageways.

5. The gas turbine engine of claim 2 , wherein the inlet and outlet passageways are arranged in alternating sequence in the circumferential direction.

6. The gas turbine engine of claim 5 , wherein the inlet and outlet passageways extend axially and parallel with each other, wherein the coolant flows through the inlet passageway in a first axial direction and through the outlet passageway in a second axial direction opposite the first axial direction, wherein the micropassageways further include a circumferentially extending first header passageway with which an axially terminal end of each outlet passageway connects and a circumferentially extending second header passageway with which an axially terminal end of each inlet passageway connects, wherein the axially terminal end of each outlet passageway and the axially terminal end of each inlet passageway are located adjacent each other such that the first header passageway and the second header passageway are located adjacent each other, and wherein the at least one transfer section extends circumferentially between at least one outlet passageway and inlet passageway.

7. The gas turbine engine of claim 1 , wherein the stator includes electrical windings disposed radially outward of the annular core.

8. The gas turbine engine of claim 1 , wherein the rotor includes a magnet arranged radially outward of the stator and separated therefrom by an air gap.

9. The gas turbine engine of claim 1 , wherein the coolant is air received from the fan.

10. The gas turbine engine of claim 1 , wherein the electric device is one of an electric motor, an electric generator, and an electric motor-generator.

11. The gas turbine engine of claim 1 , wherein the electric device is positioned between the fan and the compressor rotor.

12. A gas turbine engine for use in an aircraft, the engine comprising

a low pressure spool including a fan arranged at a forward end of the engine, a low pressure turbine rotor arranged at an aft end of the engine, a low pressure drive shaft extending along an axis and rotationally coupling the fan to receive driven rotation from the low pressure turbine rotor,

an electric device including a stator having an annular core, a rotor rotationally coupled to the low pressure drive shaft and disposed about the stator in electromagnetic communication, and

a microchannel cooling system arranged radially inward of the stator in thermal communication with the annular core to pass coolant for removing heat from the stator, the microchannel cooling system including a housing and a network of micropassageways within the housing, the housing abutting a radially inner side of the stator,

wherein the network of micropassageways includes at least one micropassageway that extends longitudinally parallel to the axis and at least one micropassageway that extends circumferentially relative to the axis such that the coolant flowing though microchannel cooling system primarily only flows axially parallel with the axis and circumferentially relative to the axis.

13. The gas turbine engine of claim 12 , wherein the micropassageways include inlet passageways for receiving coolant and outlet passageways for discharging heated coolant.

14. The gas turbine engine of claim 13 , wherein each inlet passageway is connected with at least one of the outlet passageways by at least one transfer section to pass coolant in thermal communication with the annular core.

15. The gas turbine engine of claim 14 , wherein the inlet and outlet passageways are arranged in alternating sequence in the circumferential direction.

16. The gas turbine engine of claim 12 , wherein the stator includes electrical windings disposed radially outward of the annular core.

17. The gas turbine engine of claim 12 , wherein the rotor includes a magnet arranged radially outward of the stator and separated therefrom by an air gap.

18. The gas turbine engine of claim 12 , wherein the coolant is air received from the fan.

19. The gas turbine engine of claim 12 , wherein the electric device is one of an electric motor, an electric generator, and an electric motor-generator.

20. An electrical device of gas turbine engine, the electrical device comprising

a stator having an annular core disposed about an axis,

a rotor rotationally coupled to a shaft and disposed about the stator in electromagnetic communication, and

a microchannel cooling system arranged radially inward of the stator and in thermal communication with the annular core to pass coolant for removing heat from the stator, the microchannel cooling system including a housing and a network of micropassageways within the housing, the housing abutting a radially inner side of the stator,

wherein each micropassageway of the network of micropassageways extends longitudinally parallel to the axis or circumferentially relative to the axis such that the coolant flowing though microchannel cooling system primarily only flows axially parallel with the axis and circumferentially relative to the axis.