A counter-flow heat exchanger is provided that includes: a first fluid path having a first supply tube connected to a first transition area separating the first fluid path into a first array of first passageways, with the first array of first passageways merging at a first converging area into a first discharge tube; and a second fluid path having a second supply tube connected to a second transition area separating the second fluid path into a second array of second passageways, with the second array of second passageways merge at a second converging area into a second discharge tube. The first passageways and the second passageways have a substantially helical path around the centerline of the counter-flow heat exchanger. Additionally, the first array and the second array are arranged together such that each first passageway is adjacent to at least one second passageway.

A heat exchanger is configured to adjust a flow restriction of flow passages through the heat exchanger in response to changes in temperature of elements that define at least a portion of the flow passages. The elements include a first material having a first coefficient of thermal expansion, and a second material having a second coefficient of thermal expansion that is different from the first coefficient of thermal expansion.

A heat exchanger manifold configured to receive or discharge a first fluid includes a primary fluid channel and a plurality of secondary fluid channels. The primary fluid channel includes a fluid port and a first branched region distal to the fluid port. The plurality of secondary fluid channels are fluidly connected to the primary fluid channel at the first branched region. Each of the plurality of secondary fluid channels includes a first end and a second end opposite the first end. Each of the plurality of secondary fluid channels extends radially from the first branched region at the first end and has an equal length from a center of the first branched region to the second end.

A heat exchanger is provided with a unitary, single-piece structure that can be formed via 3D printing, for example. The heat exchanger includes a main body a plurality of plates stacked and integrally formed with the body. First fluid channels are defined by gaps in the material of the main body, and second fluid channels are defined by gaps in the material of the main body and are stacked with the first fluid channels in alternating fashion, separated by the plates. Each of the first fluid channels define a first flow path, and each of the second fluid channels define a second flow path. A portion of the first flow paths overlap, and are oriented opposite to, a portion of the second flow paths. Another portion of the first flow paths overlap, and are oriented transverse to, another portion of the second flow paths.

A heat exchanger is provided with a unitary, single-piece structure that can be formed via 3D printing, for example. The heat exchanger includes a main body defining a first fluid inlet port, a first fluid outlet port, a second fluid inlet port, and a second fluid outlet port, wherein each of these fluid ports are integrally formed with the main body. A plurality of plates are stacked and integrally formed with the body. First fluid channels are defined by gaps in the material of the main body and are in fluid communication with the first fluid inlet port. Second fluid channels are defined by gaps in the material of the main body and are in fluid communication with the second fluid inlet port. The first fluid channels and the second fluid channels are interposed between the plates in alternating fashion along the stacked arrangement.

A heat exchanger is provided with a unitary, single-piece structure that can be formed via 3D printing, for example. The heat exchanger includes a main body a plurality of plates stacked and integrally formed with the body. First fluid channels are defined by gaps in the material of the main body, and second fluid channels are defined by gaps in the material of the main body and are stacked with the first fluid channels in alternating fashion, separated by the plates. Each of the first fluid channels are fluidly coupled to an inlet manifold and an outlet manifold. At least one of the manifolds is provided with surface features that improve heat exchange within the manifold. The surface features may be, for example, projections such as fins that increase surface area contact between the fluid in the manifold and the interior wall of the manifold.

A heat exchanger is provided with a unitary, single-piece structure that can be formed via 3D printing, for example. The heat exchanger includes a main body a plurality of plates stacked and integrally formed with the body. First fluid channels are defined by gaps in the material of the main body, and second fluid channels are defined by gaps in the material of the main body and are stacked with the first fluid channels in alternating fashion, separated by the plates. Each of the first fluid channels are fluidly coupled to an inlet manifold and an outlet manifold. A jumper pipe is fluidly coupled to and between an inlet port and the inlet manifold. In an embodiment, the jumper pipe is curved at one end thereof to intersect the inlet manifold at a generally perpendicular angle.

A heat exchanger is provided with a unitary, single-piece structure that can be formed via 3D printing, for example. The heat exchanger includes a main body a plurality of plates stacked and integrally formed with the body. First fluid channels are defined by gaps in the material of the main body, and second fluid channels are defined by gaps in the material of the main body and are stacked with the first fluid channels in alternating fashion, separated by the plates. Each of the first fluid channels are fluidly coupled to two manifolds, and each of the second fluid channels are fluidly coupled to two more manifolds. One of the manifolds has a reduced interior volume to control and normalize fluid flow through the heat exchanger.

A multilayered material system includes at least one of a liner sheet and a cellular core, and a multilayered composite joined to the at least one of a liner sheet and a cellular core. The multilayered composite includes hollow microspheres dispersed within a metallic matrix material.

A method for fabricating an integrated heat pipe is disclosed. The integrated heat pipe includes a porous wick structure, a solid conducting structure, and an integrated part. In a CAD model, the porous wick structure is represented as a simple solid having a finite amount of mechanical interference; the solid conducting structure and the integrated part are represented as simple solids. After incorporating the CAD model into a 3D-printer build file, 3D-printer parameters representing the porous wick structure of the integrated heat pipe are assigned to a porous region component model within the 3D-printer build file, and standard 3D-printer parameters representing the solid conducting structure and the integrated part are assigned to a solid region component model within the 3D-printer build file. The 3D-printer build file is utilized to print the integrated heat pipe on a 3D printer.