Abstract: Aircraft electric motors are described. The aircraft electric motors include a cooling system comprising an annular heat exchanger, a motor housing arranged radially inward from the heat exchanger, the motor housing defining a rotor-stator cavity and a gear assembly cavity, a rotor sleeve arranged within the rotor-stator cavity, a gear assembly arranged within the gear assembly cavity, a first shaft operably coupled to the rotor sleeve and configured to be rotationally driven by the rotor sleeve to drive rotation of a portion of the gear assembly, and a second shaft operably coupled to the gear assembly and configured to be rotationally driven by the gear assembly.

Abstract: An electric motor system includes an electric motor, and a thermal management system. The thermal management system includes a two-phase refrigerant circuit circulating a flow of refrigerant through the electric motor, and a refrigerant-air heat exchanger fluidly connected to the electric motor via the two-phase refrigerant circuit, such that the flow of refrigerant is boiled via heat generated by the electric motor, and returned to a subcooled liquid state to cool the electric motor. A method of dissipating thermal energy from an electric motor includes urging a flow of refrigerant through an electric motor, thereby boiling the flow of refrigerant, directing the flow of refrigerant from the electric motor to a refrigerant-air heat exchanger via a two-phase refrigerant circuit, and cooling the refrigerant to a sub-cooled liquid state at the refrigerant-air heat exchanger via thermal energy exchange with a flow of air through the refrigerant-air heat exchanger.

Abstract: A cooling system for a superconducting electric machine may comprise a fluid reservoir and a first fluid comprising a first mixture of hydrogen and helium configured to be stored in the fluid reservoir. A plurality of conduits may be fluidly coupled to the fluid reservoir and may form a closed loop between the fluid reservoir and the superconducting electric machine.

Abstract: A stator and a motor including a stator. The stator includes a stator hub, a plurality of stator teeth extending from the stator hub that define a stator slot having a stator slot base, at least one winding disposed in the stator slot, and one or more oscillating heat pipes disposed at least partially in the at least one winding. The at least one winding is held apart from the stator slot base so that a cooling channel is defined between an inner winding portion of the at least one winding and a portion of the one or more oscillating heat pipes is disposed in the channel so cooling fluid can be passed between the stator slot base and the inner winding portion to cool the inner winding portion via at least operation of the one or more oscillating heat pipes.

Abstract: A heat exchanger includes a heat exchanger core. The heat exchanger core includes a first fin and a second fin. The second fin is spaced apart from the first fin. The heat exchanger core also includes a primary passage defined between the first fin and the second fin and extending through the heat exchanger core. The heat exchanger core also includes a plurality of airfoils extending through the first fin, the primary passage, and the second fin. At least one airfoil of the plurality of airfoils includes a secondary passage. The secondary passage extends through the heat exchanger core within the at least one airfoil transverse to the primary passage.

Abstract: A temperature control system in an aircraft passenger service unit is disclosed. In embodiments, the system includes a swirl chamber configured to receive an inlet air stream, and a vortex tube configured to receive the inlet air stream from the swirl chamber and separate the inlet air stream into a warmer air stream and a cooler air stream. In embodiments, the system further includes a nozzle configured to direct a temperature-controlled air stream into a passenger space of an aircraft; wherein the nozzle is configured to be selectably adjusted in order to selectively blend the warmer air stream and the cooler air stream in order to generate the temperature-controlled air stream.

Abstract: Aircraft electric motors are described. The aircraft electric motors include a motor unit having a rotor and a stator, wherein the stator includes a plurality of windings and cooling channels arranged to provide cooling to the plurality of windings, a drive unit configured to drive operation of the motor unit, and a cooling system. The cooling system includes an oscillating heat pipe containing a first working fluid, wherein the oscillating heat pipe is arranged to pick up heat from at least one winding, the oscillating heat pipe having an evaporator section arranged in thermal contact with the at least one winding and a condenser section arranged away from the evaporator section and a heat pickup portion arranged to receive a second working fluid to remove heat from the condenser section of the oscillating heat pipe.

Abstract: Aircraft electric motors are described. The aircraft electric motors includes a motor unit having a rotor and a stator, wherein the stator includes a plurality of windings and cooling channels arranged to provide cooling to the plurality of windings, a drive unit configured to drive operation of the motor unit, and a cooling system. The cooling system includes at least one cooling channel integrally formed within at least one winding, wherein the at least one cooling channel comprises an inlet to receive a two-phase cooling fluid and an outlet configured to discharge the two-phase cooling fluid, wherein a cross-sectional area of the at least one cooling channel at the inlet is less than a cross-sectional area of the at least one cooling channel at the outlet.

Abstract: Aircraft electric motors are described. The aircraft electric motors include a motor unit having a rotor and a stator, wherein the stator includes a plurality of windings and cooling channels arranged to provide cooling to the plurality of windings, a drive unit configured to drive operation of the motor unit, and a cooling system having at least one directional feature forming a portion of at least one cooling channel, the at least one directional feature configured to prevent backflow of a cooling fluid that passes through the at least one cooling channel.

Abstract: Aircraft electric motors include a motor unit having a rotor and a stator. The stator includes a plurality of windings and cooling channels arranged to provide cooling thereto. A drive unit is configured to drive operation of the motor unit. A cooling system includes a working fluid arranged within a cooling fluid flow path, wherein the cooling fluid flow path includes a liquid cooling path configured to direct flow of the working fluid through, at least, the cooling channels of the motor unit and a vapor cooling path configured to direct flow of the working fluid through the drive unit and a separator arranged upstream of each of the liquid cooling path and the vapor cooling path and configured to direct a liquid portion of the working fluid into the liquid cooling path and configured to direct a vapor portion of the working fluid into the vapor cooling path.

Abstract: Power and cooling systems including a drive system, a power generation unit, and a cooled fluid generation unit. A primary working fluid that is expanded within a turbine of the drive system and compressed within compressors in a closed-loop cycle. The power generation unit includes a generator and a heat source configured to heat the primary working fluid prior to injection into the turbine. T cooled fluid generation unit includes an ejector downstream of the compressors and a separator arranged downstream of the ejector and configured to separate liquid and gaseous portions of the primary working fluid. The gaseous portion is directed to the compressors and the liquid portion is directed to an evaporator heat exchanger to generate cooled fluid.

Abstract: A stator and a motor including a stator. The stator includes a stator hub, a plurality of stator teeth extending from the stator hub that define a stator slot having a stator slot base, at least one winding disposed in the stator slot, and one or more oscillating heat pipes disposed at least partially in the at least one winding. The at least one winding is held apart from the stator slot base so that a cooling channel is defined between an inner winding portion of the at least one winding and a portion of the one or more oscillating heat pipes is disposed in the channel so cooling fluid can be passed between the stator slot base and the inner winding portion to cool the inner winding portion via at least operation of the one or more oscillating heat pipes.

Abstract: A shell-and-tube heat exchanger and an air conditioning system. The shell-and-tube heat exchanger includes: a shell provided with a liquid inlet and an vapor outlet, the vapor outlet being disposed at an top portion of the shell; and a heat exchange tube bundle disposed in the shell in an axial direction of the shell; wherein the heat exchange tube bundle includes: a plurality of first heat exchange tubes located at an upper portion, the first heat exchange tubes having a first spacing therebetween; and a plurality of second heat exchange tubes located at a lower portion, the second heat exchange tubes having a second spacing therebetween; the first spacing is different from the second spacing.

Abstract: A heat exchange conduit includes a body having a first portion including a first flow channel and a second portion including a second flow channel. A cross-section of the heat exchange conduit varies over a length of the heat exchange conduit.

Abstract: A nonlinear coolant tube adapted for use in a heat exchanger core that is configured to port a hot fluid therethrough and a cold fluid therethrough while maintaining isolation of the hot fluid from the cold fluid, and including a hot circuit defining a hot circuit inlet, a hot circuit outlet, a first edge, and a second edge, the first edge distal the second edge, the first edge proximate the hot circuit inlet and the second edge proximate the hot circuit outlet. The nonlinear coolant tube is configured to provide a non-uniform heat transfer profile between the hot fluid and the cold fluid from the first edge to the second edge, such that a thermal resistance of the nonlinear coolant tube near the first edge is greater than the thermal resistance of the nonlinear coolant tube near the second edge.

Abstract: A refrigeration system can include a main flow circuit configured to flow a refrigerant therethrough and a heat input disposed in the main flow circuit and configured to receive heat and transfer the heat to the refrigerant in the main flow circuit to output heated refrigerant flow. The system can include a passive pump disposed in the main flow circuit downstream of the heat input configured to receive the heated refrigerant flow from the heat input and to use the heated refrigerant flow to generate a vacuum at a pump port and a condenser disposed in the main flow circuit downstream of the passive pump for receiving flow from the passive pump. The condenser can be configured to receive heat from the heated refrigerant flow and reject heat to cool the heated refrigerant flow to output partially cooled refrigerant flow. An outlet of the condenser can be upstream of the heat input.

Abstract: Aircraft electric motors are described. The aircraft electric motors include a cooling system comprising an annular heat exchanger, a motor housing arranged radially inward from the heat exchanger, the motor housing defining a rotor-stator cavity and a gear assembly cavity, a rotor sleeve arranged within the rotor-stator cavity, a gear assembly arranged within the gear assembly cavity, a first shaft operably coupled to the rotor sleeve and configured to be rotationally driven by the rotor sleeve to drive rotation of a portion of the gear assembly, and a second shaft operably coupled to the gear assembly and configured to be rotationally driven by the gear assembly.

Abstract: A temperature control system in an aircraft passenger service unit is disclosed. In embodiments, the system includes a swirl chamber configured to receive an inlet air stream, and a vortex tube configured to receive the inlet air stream from the swirl chamber and separate the inlet air stream into a warmer air stream and a cooler air stream. In embodiments, the system further includes a nozzle configured to direct a temperature-controlled air stream into a passenger space of an aircraft; wherein the nozzle is configured to be selectably adjusted in order to selectively blend the warmer air stream and the cooler air stream in order to generate the temperature-controlled air stream.

Abstract: An electric motor system includes an electric motor, and a thermal management system. The thermal management system includes a two-phase refrigerant circuit circulating a flow of refrigerant through the electric motor, and a refrigerant-air heat exchanger fluidly connected to the electric motor via the two-phase refrigerant circuit, such that the flow of refrigerant is boiled via heat generated by the electric motor, and returned to a subcooled liquid state to cool the electric motor. A method of dissipating thermal energy from an electric motor includes urging a flow of refrigerant through an electric motor, thereby boiling the flow of refrigerant, directing the flow of refrigerant from the electric motor to a refrigerant-air heat exchanger via a two-phase refrigerant circuit, and cooling the refrigerant to a sub-cooled liquid state at the refrigerant-air heat exchanger via thermal energy exchange with a flow of air through the refrigerant-air heat exchanger.

Abstract: Disclosed is a heat exchanger comprising a first flow path with an inlet, an outlet and a first surface and a second flow path with an inlet, an outlet and a second surface wherein at least one of the first surface and the second surface has a portion consisting of a shape memory alloy which has a first shape at a first temperature, a second shape at a second temperature different than the first temperature, and returns to the first shape in response to a return to the first temperature.