Abstract: Systems, apparatuses, and methods relating to heat transfer devices having nested layers of helical fluid channels. In some examples, a device for transferring heat includes a set of nested tubular walls and a plurality of helical walls intersecting each of the nested tubular walls to form one or more first channel layers nested with one or more second channel layers. Each of the first and second channel layers includes a plurality of helical fluid channels. A first intake and a first outtake are in fluid communication with one another via the plurality of helical fluid channels of each first channel layer, for flow of a first fluid through the device. A second intake and a second outtake are in fluid communication with one another via the plurality of helical fluid channels of each second channel layer, for flow of a second fluid through the device.

Abstract: Example heat exchangers and methods of use are described herein. An example heat exchanger includes a lattice structure including a plurality of conduits defining a plurality of interstitial voids between the plurality of conduits. Each of the plurality of conduits includes an inlet and an outlet, and the plurality of conduits are arranged such that, between the inlet and the outlet, each of the conduits intersects at least one other conduit to enable flow between the intersecting conduits. The example heat exchanger also includes a first manifold formed unitarily with the lattice structure, the first manifold comprising a first plurality of openings in fluid communication with each inlet of the plurality of conduits. The example heat exchanger further includes a phase change material (PCM) disposed within and substantially filling the plurality of interstitial voids.

Abstract: Methods and apparatus for cooling a surface on a flight vehicle and generating power include advancing the vehicle at a speed of at least Mach 3 to aerodynamically heat the surface. A first working fluid circulates through a first fluid loop that heats the first working fluid through a first heat intake thermally coupled to the surface and expands the first working fluid in a first thermal engine to generate a first work output. A second fluid loop has a second working fluid that receives heat from the first working fluid and a second thermal engine to generate a second work output. The first and second work outputs are operably coupled to first and second generators, respectively, to power primary or auxiliary systems on the flight vehicle.

Abstract: Systems, apparatuses, and methods relating to heat transfer devices having nested layers of helical fluid channels. In some examples, a device for transferring heat includes a set of nested tubular walls and a plurality of helical walls intersecting each of the nested tubular walls to form one or more first channel layers nested with one or more second channel layers. Each of the first and second channel layers includes a plurality of helical fluid channels. A first intake and a first outtake are in fluid communication with one another via the plurality of helical fluid channels of each first channel layer, for flow of a first fluid through the device. A second intake and a second outtake are in fluid communication with one another via the plurality of helical fluid channels of each second channel layer, for flow of a second fluid through the device.

Abstract: Methods and apparatus for cooling a surface on a flight vehicle and/or generating power include advancing the flight vehicle at a speed of at least Mach 3 to aerodynamically heat the surface. A supercritical working fluid is circulated through a fluid loop that includes compressing the supercritical working fluid through a compressor, heating the supercritical working fluid through a heat intake that is thermally coupled to the surface, expanding the supercritical working fluid in a thermal engine to generate a work output, cooling the supercritical working fluid, and recirculating the supercritical working fluid to the compressor. The work output of the thermal engine is operably coupled to the compressor, and may optionally be coupled to a generator to produce power. The supercritical working fluid absorbs heat from the surface, eliminating hot spots and permitting use of lighter and/or less expensive materials.

Abstract: Methods and apparatus for cooling a surface on a flight vehicle and generating power include advancing the vehicle at a speed of at least Mach 3 to aerodynamically heat the surface. A first working fluid circulates through a first fluid loop that heats the first working fluid through a first heat intake thermally coupled to the surface and expands the first working fluid in a first thermal engine to generate a first work output. A second fluid loop has a second working fluid that receives heat from the first working fluid and a second thermal engine to generate a second work output. The first and second work outputs are operably coupled to first and second generators, respectively, to power primary or auxiliary systems on the flight vehicle.

Abstract: A condenser having passages of varying geometry for cooling of fluid. The condenser apparatus includes substantially parallel tubes each defining a channel and having an inlet at a first end and an outlet at a second end, the first end having a greater hydraulic diameter than the second end. Inlet and outlet manifolds are provided. The tubes may be oriented substantially vertically with the inlets above the respective outlets. A heat exchanger core comprises the tubes and substantially horizontally oriented fin material connecting the tubes. The tubes may receive a relatively higher temperature vapor or vapor and liquid mixture into the inlets of the tubes, around the tubes coolant flows substantially horizontally to remove heat from the tubes, and relatively cooler saturated liquid is discharged from the outlets. In one embodiment, the tube's channel splits into multiple channels to reduce the hydraulic diameter and increase the surface area ratio.

Abstract: Methods and apparatus for cooling a surface on a flight vehicle and/or generating power include advancing the flight vehicle at a speed of at least Mach 3 to aerodynamically heat the surface. A supercritical working fluid is circulated through a fluid loop that includes compressing the supercritical working fluid through a compressor, heating the supercritical working fluid through a heat intake that is thermally coupled to the surface, expanding the supercritical working fluid in a thermal engine to generate a work output, cooling the supercritical working fluid, and recirculating the supercritical working fluid to the compressor. The work output of the thermal engine is operably coupled to the compressor, and may optionally be coupled to a generator to produce power. The supercritical working fluid absorbs heat from the surface, eliminating hot spots and permitting use of lighter and/or less expensive materials.

Abstract: A heat exchanger with non-circular tubes arranged in a louvered fashion. In one embodiment the tubes include a first plurality of hollow members extending in a first direction, a second plurality of hollow members extending in a second direction different from the first direction, and a third plurality of hollow members extending in a third direction different from the first direction and from the second direction, the hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members intersecting at a plurality of hollow nodes.

Abstract: A heat pipe comprises a tube and protrusions. The tube has an internal surface, an external surface, and a length running from a first end to a second end. The protrusions are on the internal surface. A first cross-section of the protrusions at a first location of the length of the tube is different from a second cross-section of the protrusions at a second location of the length of the tube. The tube and the protrusions are monolithic.

Abstract: An aircraft including an airframe, a propulsion system, and a heat exchanger is presented. The heat exchanger of the aircraft may include (i) a structural body including a plurality of hollow channels, (ii) a first fluid positioned within the plurality of hollow channels of the structural body, (iii) a plurality of openings positioned on a first side of the structural body and in fluid communication with the plurality of hollow channels, (iv) a wick structure positioned on the first side of the structural body, and further positioned adjacent to an exterior of the plurality of hollow channels and in fluid communication with the plurality of openings, (v) an inlet to the structural body operable to provide a second fluid from an aircraft system, and (vi) an outlet from the structural body operable to receive the second fluid after receiving heat from the first fluid.

Abstract: A condenser having passages of varying geometry for cooling of fluid. The condenser apparatus includes substantially parallel tubes each defining a channel and having an inlet at a first end and an outlet at a second end, the first end having a greater hydraulic diameter than the second end. Inlet and outlet manifolds are provided. The tubes may be oriented substantially vertically with the inlets above the respective outlets. A heat exchanger core comprises the tubes and substantially horizontally oriented fin material connecting the tubes. The tubes may receive a relatively higher temperature vapor or vapor and liquid mixture into the inlets of the tubes, around the tubes coolant flows substantially horizontally to remove heat from the tubes, and relatively cooler saturated liquid is discharged from the outlets. In one embodiment, the tube's channel splits into multiple channels to reduce the hydraulic diameter and increase the surface area ratio.

Abstract: A condenser having passages of varying geometry for cooling of fluid. The condenser apparatus includes substantially parallel tubes each defining a channel and having an inlet at a first end and an outlet at a second end, the first end having a greater hydraulic diameter than the second end. Inlet and outlet manifolds are provided. The tubes may be oriented substantially vertically with the inlets above the respective outlets. A heat exchanger core comprises the tubes and substantially horizontally oriented fin material connecting the tubes. The tubes may receive a relatively higher temperature vapor or vapor and liquid mixture into the inlets of the tubes, around the tubes coolant flows substantially horizontally to remove heat from the tubes, and relatively cooler saturated liquid is discharged from the outlets. In one embodiment, the tube's channel splits into multiple channels to reduce the hydraulic diameter and increase the surface area ratio.

Abstract: An aircraft including an airframe, a propulsion system, and a heat exchanger is presented. The heat exchanger of the aircraft may include (i) a structural body including a plurality of hollow channels, (ii) a first fluid positioned within the plurality of hollow channels of the structural body, (iii) a plurality of openings positioned on a first side of the structural body and in fluid communication with the plurality of hollow channels, (iv) a wick structure positioned on the first side of the structural body, wherein the wick structure is positioned adjacent to an exterior of the plurality of hollow channels and in fluid communication with the plurality of openings, (v) an inlet to the structural body operable to provide a second fluid from an aircraft system, and (vi) an outlet from the structural body operable to receive the second fluid after receiving heat from the first fluid.

Abstract: Example heat exchangers and methods of use are described herein. An example heat exchanger includes a lattice structure including a plurality of conduits defining a plurality of interstitial voids between the plurality of conduits. Each of the plurality of conduits includes an inlet and an outlet, and the plurality of conduits are arranged such that, between the inlet and the outlet, each of the conduits intersects at least one other conduit to enable flow between the intersecting conduits. The example heat exchanger also includes a first manifold formed unitarily with the lattice structure, the first manifold comprising a first plurality of openings in fluid communication with each inlet of the plurality of conduits. The example heat exchanger further includes a phase change material (PCM) disposed within and substantially filling the plurality of interstitial voids.

Abstract: A method of manufacturing a heat exchanger including a heat exchanger core of a first material, the method including additive manufacturing a sacrificial scaffold of a second material, the sacrificial scaffold corresponding in shape to that of the heat exchanger core, coating the sacrificial scaffold with a layer of the first material, and removing the sacrificial scaffold to leave behind the heat exchanger core with an integrated self-aligned passage.

Abstract: Disclosed embodiments include a structurally integrated thermal management system that uses the structure of an aerospace vehicle as part of the heat dissipation system. In this system, structural elements of the aerospace vehicle function as a thermal bus, and are thermally connected with heat-generating electrical components, so that heat from those components is directed away from the component by the structure of the vehicle itself, into lower temperature surfaces of the vehicle.

Abstract: A heat pipe comprises a tube and protrusions. The tube has an internal surface, an external surface, and a length running from a first end to a second end. The protrusions are on the internal surface. A first cross-section of the protrusions at a first location of the length of the tube is different from a second cross-section of the protrusions at a second location of the length of the tube. The tube and the protrusions are monolithic.

Abstract: A method of manufacturing a heat exchanger including a heat exchanger core of a first material, the method including additive manufacturing a sacrificial scaffold of a second material, the sacrificial scaffold corresponding in shape to that of the heat exchanger core, coating the sacrificial scaffold with a layer of the first material, and removing the sacrificial scaffold to leave behind the heat exchanger core with an integrated self-aligned passage.

Abstract: A sensor system for a laminated structure may include a sensor assembly disposed between a first layer and a second layer of the laminated structure. The sensor assembly may include a first anchor member and a second anchor member spaced at a predetermined distance from one another. A sensor chamber is formed between the first and second anchor members. The sensor assembly may also include a sensing line extending through the anchor members and the sensor chamber. The sensing line may include a configuration within the sensor chamber for sensing one of stress forces within the laminated structure, temperature or temperature changes within the laminated structure. A first transport tube may extend from the first anchor member opposite the sensor chamber and a second transport tube may extend from the second anchor member opposite the sensor chamber. The sensing line extends through the first and second transport tubes.