Provided is an apparatus for generating electricity comprising a gas propellant chamber and one or more generators. The gas propellant chamber comprises a compressor, a nuclear fuel chamber, and a turbine assembly, wherein a drive shaft extending axially through the gas propellant chamber couples the compressor to the turbine assembly and wherein the nuclear fuel chamber is a rotating nuclear fuel chamber configured to rotate axially along the drive shaft to which the compressor and the turbine assembly are coupled.

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.

Aircraft propulsion systems including a closed loop-supercritical fluid system having a turbine, a cooler heat exchanger, a compressor, and a recovery heat exchanger arranged along a closed-loop flow path of a supercritical fluid. A shaft is operably coupled to the turbine and configured to be rotationally driven by the turbine. A fan is configured to generate thrust, the fan operably coupled to the shaft to be rotationally driven by the shaft. A burner is configured to combust a fuel and air from the fan to generate a combusted gas and supply said combusted gas to the recovery heat exchanger of the closed loop-supercritical fluid system and out an exhaust nozzle.

A heat exchanger for heat exchange between a first fluid and a second fluid has a plurality of tube sections, each having; an interior for passing the first fluid; an exterior for exposure to the second fluid; a first leg; a second leg; and a turn joining the first leg to the second leg. A has: fiber members passing between legs of the tube sections; and an end plate.

A heat exchanger for heat exchange between a first fluid and a second fluid has a plurality of tube sections, each having; an interior for passing the first fluid; an exterior for exposure to the second fluid; a first leg; a second leg; and a turn joining the first leg to the second leg. A has: fiber members passing between legs of the tube sections; and an end plate.

Techniques for utilizing excess heat generated by an oven to generate electricity are provided. In one example, an oven can comprise a coolant pathway positioned adjacent to a hollow space within the oven, wherein the hollow space can contain heat. The oven can also comprise a chamber in fluid communication with the coolant pathway. The oven can further comprise a turbine in fluid communication with the chamber and an outlet. Moreover, the oven can comprise a generator connected to the turbine, wherein rotation of the turbine can power the generator.

Techniques for utilizing excess heat generated by an oven to generate electricity are provided. In one example, an oven can comprise a coolant pathway positioned adjacent to a hollow space within the oven, wherein the hollow space can contain heat. The oven can also comprise a chamber in fluid communication with the coolant pathway. The oven can further comprise a turbine in fluid communication with the chamber and an outlet. Moreover, the oven can comprise a generator connected to the turbine, wherein rotation of the turbine can power the generator.

A power plant including a compressor, a combustion chamber and a turbine, and a compressor air line, which connects the compressor to the combustion chamber, a first heat exchanger connected into the compressor air line and into an exhaust line branching off the turbine. A first expander is arranged between the first heat exchanger and the combustion chamber in the compressor air line, and the first expander and the compressor are arranged on a common shaft.

Aircraft power plants including combustion engines, and associated methods for recuperating waste heat from such aircraft power plants are described. A method includes transferring the heat rejected by the internal combustion engine to supercritical CO.sub.2 (sCO.sub.2) used as a working fluid in a heat engine. The heat engine converts at least some the heat transferred to the sCO.sub.2 to mechanical energy to perform useful work onboard the aircraft.