This stacked heat exchanger is provided with: a high temperature layer that comprises a plurality of channels into which a high temperature-side fluid is introduced; and a low temperature layer that is superposed on the high temperature layer and comprises a plurality of channels into which a low temperature-side fluid is introduced, said low temperature-side fluid being at a temperature that is lower than the temperature of the high temperature-side fluid. Each one of the plurality of channels of the low temperature layer has: an upstream-side part in which at least some of the low temperature-side fluid evaporates by being heated by the high temperature-side fluid that flows within the high temperature layer; and a downstream-side part in which the low temperature-side fluid that has evaporated in the upstream-side part is heated by the high temperature-side fluid that flows within the high temperature layer. The ratio of the areas of the plurality of upstream-side parts in a predetermined area of the low temperature layer is lower than the ratio of the areas of the plurality of downstream-side parts in the predetermined area of the low temperature layer.

A heat pipe is provided having a hollow body defining an interior vapor space, evaporator and condenser regions, a wick structure lining an inner wall of the hollow body, and a working fluid disposed in the hollow body, wherein a path for the working fluid in liquid state extends from the condenser region toward the evaporator region or wherein the wick structure extends along a direction from a first end of the hollow body toward the second end, and wherein the wick structure includes first and second regions that extend along the path or direction and that each have wick particles defining respective pore sizes that are different from one another.

A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

Embodiments described herein generally relate to a multi-mode heat transfer system. The heat transfer system includes an emitter device. The emitter device includes an inner core surrounded by an outer core having a thickness and an outer surface. A composite material pattern extends through at least a portion of the outer surface and at least a portion of the thickness of the outer core and is thermally coupled to the inner core. The composite material pattern in combination with an optimized emissivity surface coating/paint profile directs a heat from the inner core to an object other than the emitter device.

A heat exchanger includes a first flow path through which a first fluid flows, a second flow path through which a second fluid flows, and an adjustment layer disposed between the first flow path and the second flow path adjacent to each other and that adjusts an amount of heat exchange between the first flow path and the second flow path. The adjustment layer includes a first portion and a second portion having a heat transfer performance lower than that of the first portion, and has a heat transfer performance varied depending on a position in the adjustment layer.

A heat exchanger includes a first flow path through which a first fluid flows, a second flow path through which a second fluid flows, and an adjustment layer disposed between the first flow path and the second flow path adjacent to each other and that adjusts an amount of heat exchange between the first flow path and the second flow path. The adjustment layer includes a first portion and a second portion having a heat transfer performance lower than that of the first portion, and has a heat transfer performance varied depending on a position in the adjustment layer.

Disclosed herein are various technologies pertinent to rocket engines, including injector, thrust chamber, and electrical turbopump devices that may be combined to provide a more efficient rocket engine. The electrical turbopump impeller includes a coolant bypass port fluidically connected with a coolant passage that passes through the impeller central hub and allows some of the propellant that is acted on by the impeller to bypass the impeller outlet and instead be flowed into the electrical turbopump housing so that the diverted propellant may be used to cool the various components housed within the housing such as the electric motor bearings, stator, rotor, and electronics.

A monolithic heater body may include a combustor body, a hot-side heat exchanger body, and an eductor body. The combustor body may define a combustion chamber and a conditioning conduit circumferentially surrounding the combustion chamber. The conditioning conduit may fluidly communicate with the combustion chamber at a distal portion of the combustion chamber. The hot-side heat exchanger body may define a hot-side heat exchanger that includes a heating fluid pathway fluidly communicating with a proximal portion of the combustion chamber. The eductor body may define an eduction pathway fluidly communicating with a downstream portion of the heating fluid pathway and a proximal portion of the conditioning conduit.

A monolithic heater body may include a combustor body, a hot-side heat exchanger body, and an eductor body. The combustor body may define a combustion chamber and a conditioning conduit circumferentially surrounding the combustion chamber. The conditioning conduit may fluidly communicate with the combustion chamber at a distal portion of the combustion chamber. The hot-side heat exchanger body may define a hot-side heat exchanger that includes a heating fluid pathway fluidly communicating with a proximal portion of the combustion chamber. The eductor body may define an eduction pathway fluidly communicating with a downstream portion of the heating fluid pathway and a proximal portion of the conditioning conduit.