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 system for energy conversion, the system including a closed cycle engine containing a volume of working fluid, the engine comprising a first chamber defining an expansion chamber and a second chamber defining a compression chamber each separated by a piston attached to a connection member of a piston assembly, and wherein the engine comprises a heater body in thermal communication with the first chamber, and further wherein the engine comprises a cold side heat exchanger in thermal communication with the second chamber, and wherein a third chamber is defined within the piston, wherein the third chamber is in selective flow communication with the first chamber, the second chamber, or both.

A thermal management system for transferring heat from a heat load includes a composite structural member that supports a heat load source and a heat transfer member in thermal contact with the composite structural member, and in thermal contact with a heat sink. The system further includes at least one thermally-conductive first fastener that is in thermal contact with the heat transfer member, couples the heat load source to the composite structural member, and conducts heat from the heat load source into the heat transfer member. The heat transfer member conducts heat from the thermally-conductive first fastener to the heat sink.

A thermal management system for transferring heat from a heat load includes a composite structural member that supports a heat load source and a heat transfer member in thermal contact with the composite structural member, and in thermal contact with a heat sink. The system further includes at least one thermally-conductive first fastener that is in thermal contact with the heat transfer member, couples the heat load source to the composite structural member, and conducts heat from the heat load source into the heat transfer member. The heat transfer member conducts heat from the thermally-conductive first fastener to the heat sink.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly, that includes a first heater body and a first engine body. The first heater body may define a first portion of a first monolithic body or at least a portion of a first monolithic body-segment. The first engine body may define a second portion of the first monolithic body or at least a portion of a second monolithic body-segment operably coupled or operably couplable to the first heater body. The engine assembly may include a second heater body and/or a second engine body. The second heater body may define a portion of a second monolithic body or a third monolithic body-segment. The second engine body may define a portion of the second monolithic body or a fourth monolithic body-segment operably coupled or operably couplable to the second heater body and/or the first engine body.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly, that includes a first heater body and a first engine body. The first heater body may define a first portion of a first monolithic body or at least a portion of a first monolithic body-segment. The first engine body may define a second portion of the first monolithic body or at least a portion of a second monolithic body-segment operably coupled or operably couplable to the first heater body. The engine assembly may include a second heater body and/or a second engine body. The second heater body may define a portion of a second monolithic body or a third monolithic body-segment. The second engine body may define a portion of the second monolithic body or a fourth monolithic body-segment operably coupled or operably couplable to the second heater body and/or the first engine body.

Solid-state thermoclines with internal baffle structures are in used in place of heat exchangers in a closed thermodynamic cycle power generation or energy storage system, such as a closed Brayton cycle system. The baffles limit the conductive and/or radiative transfer of heat between a solid thermal medium within different zones defined by the baffle structures.

Solid-state thermoclines with internal baffle structures are in used in place of heat exchangers in a closed thermodynamic cycle power generation or energy storage system, such as a closed Brayton cycle system. The baffles limit the conductive and/or radiative transfer of heat between a solid thermal medium within different zones defined by the baffle structures.

A monolithic combustor body may provide multi-stage combustion. A combustor body may include a combustion chamber body and a plurality of heating walls that include a heat sink. The combustion chamber body may be disposed annularly about a longitudinal axis and defining a combustion chamber. The plurality of heating walls may include heat sink. The plurality of heating walls may occupy a radially or concentrically outward position relative to the combustion chamber and may define a corresponding plurality of combustion-gas pathways fluidly communicating with at least a proximal portion of the combustion chamber. During operation, the combustor body may exhibit multi-stage combustion that includes a first combustion zone occupying a distal or medial position of the combustion chamber relative to the longitudinal axis, and a second combustion zone occupying a proximal position relative to the first combustion zone and a radially or concentrically outward position of the combustion chamber and/or a radially or concentrically inward position of the plurality of combustion-gas pathways.

A monolithic combustor body may provide multi-stage combustion. A combustor body may include a combustion chamber body and a plurality of heating walls that include a heat sink. The combustion chamber body may be disposed annularly about a longitudinal axis and defining a combustion chamber. The plurality of heating walls may include heat sink. The plurality of heating walls may occupy a radially or concentrically outward position relative to the combustion chamber and may define a corresponding plurality of combustion-gas pathways fluidly communicating with at least a proximal portion of the combustion chamber. During operation, the combustor body may exhibit multi-stage combustion that includes a first combustion zone occupying a distal or medial position of the combustion chamber relative to the longitudinal axis, and a second combustion zone occupying a proximal position relative to the first combustion zone and a radially or concentrically outward position of the combustion chamber and/or a radially or concentrically inward position of the plurality of combustion-gas pathways.