Heat exchangers, heat exchanger systems, and hypersonic vehicles are provided. For example, a heat exchanger is provided that comprises a first chamber for receipt of a flow of cool fluid and a second chamber for receipt of a flow of hot fluid. The heat exchanger further comprises a buffer fluid flowpath for circulation of a buffer fluid therethrough. The buffer fluid circulates within the buffer fluid flowpath disposed between the first chamber and the second chamber to transfer heat from the hot fluid to the cool fluid. In certain embodiments, a hypersonic vehicle comprises such a heat exchanger, and the cool fluid is cryogenic or near-cryogenic fuel of the hypersonic vehicle and the hot fluid is engine bleed air from a hypersonic propulsion engine of the vehicle.

A turbofan gas turbine engine includes, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, and a turbine module. The fan assembly includes fan blades defining a corresponding fan area (A.sub.FAN). The heat exchanger module is in fluid communication with the fan assembly by an inlet duct, and includes radially-extending vanes arranged in a circumferential array with at least one vane including a heat transfer element for heat transfer from a first fluid contained within each element to an airflow passing over a surface of each heat transfer element before entering the fan assembly inlet. Each heat transfer element extends axially along the corresponding vane, with a swept heat transfer element area (A.sub.HTE) being the wetted surface area of all heat transfer elements in contact with the airflow. A Fan to Element Area parameter F.sub.EA of A.sub.HTE/A.sub.FAN lies in the range of 47 to 132.

Composite tube assemblies and thin-walled tubing are disclosed. In embodiments, the composite tube assemblies include a functional tube and a sacrificial tube disposed within or around the functional tube. The sacrificial tube may be removed by exposure to a corrosive media, without substantially affecting the functional tube. Methods of forming composite tube assemblies and thin-walled tubing are also described.

An additively manufactured heat exchanger configured to transfer heat between a first fluid and a second fluid includes a first channel with a first wall configured to port flow of a first fluid and a second channel with a second wall configured to port flow of a second fluid. The heat exchanger also includes a barrier channel containing unprocessed build powder provided by the additive manufacturing process and is located between the first wall and the second wall. The barrier channel is configured to prevent mixing of the first fluid and the second fluid when one of the first wall and the second wall ruptures.

A heat exchanger between a fluid and an air flow, includes a heat exchange wall separating the fluid and the air flow, the heat exchange wall including a heat exchange surface that extends parallel to a longitudinal direction of the air flow and with which the air flow is in contact. The heat exchange wall includes at least one turbulence generator extending in a hollow manner in relation to the heat exchange surface.

A fuselage heat exchanger having channels for dissipating waste heat generated by fuel cells that power unmanned aerial vehicles (UAVs) or drones. A heat exchanger built into the fuselage can dissipate such waste heat. Coolant flowing through channels embedded within an aircraft fuselage panel dissipates heat to airflow around the outer surface of the fuselage.

An apparatus and method of forming a hybrid heat exchanger including a first manifold defining a first fluid inlet and a second manifold defining a second fluid inlet. A monolithic core body includes a first set of flow passages in fluid communication with the first manifold and a second set of flow passages is in communication with the second manifold. At least a portion of the first manifold or the second manifold has a tunable coefficient of thermal expansion that is less than a coefficient of thermal expansion of the structurally rigid monolithic core.

Methods, systems, and device for thermal energy storage are provided. For example, some embodiments include a thermal energy storage device that may include: a first casing wall; a second casing wall; and/or multiple support structures located between the first casing wall and the second casing wall. The multiple support structures may provide continuous thermal paths and/or continuous mechanical paths between the first casing wall and the second casing wall. The thermal energy storage device may be fabricated utilizing an additive manufacturing technique, such as direct laser metal sintering. Some embodiments may be manufactured utilizing printed metals, such as an aluminum alloy. In some embodiments, a phase-change material is charged between the first casing wall and the second casing wall. The phase-change material may include paraffin.

A method for forming a heat exchanger plate includes: securing a wave form metallic sheet to a heat exchanger plate substrate, the substrate comprising a first face and a second face opposite the first face, the securing of the wave form metallic sheet being to the first face; and removing peaks of the sheet.

A microtube heat exchanger is disclosed, including two end plates with an array of holes or openings and an array of microtubes disposed in the array of openings between the two end plates. The heat exchanger can be used in environmental control systems, including systems for aerospace applications.