An unmanned aerial vehicle (UAV) (103) is provided which includes a radioactive fuel source (111), and an external combustion engine (107) powered by said radioactive fuel source.

An unmanned aerial vehicle (UAV) (103) is provided which includes a radioactive fuel source (111), and an external combustion engine (107) powered by said radioactive fuel source.

A constant density heat exchanger and system for energy conversion 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 as the first flow control device and the second flow control device hold the volume of working fluid at constant density within the chamber.

A constant density heat exchanger and system for energy conversion 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 as the first flow control device and the second flow control device hold the volume of working fluid at constant density within the chamber.

A control system algorithm is provided for the computer control of a solid-state switching device in a Stirling-electric hybrid vehicle. The algorithm satisfies the demands for electrical energy management, regulation, allocation and distribution to the electrical system of the vehicle during the operation thereof. The control system controls the management, regulation, allocation and distribution of electrical current throughout the vehicle's electrical system in response to the commands of the vehicle operator. This includes the operation of wheel motors, electrical storage systems, the drivetrain and a plurality of other components, accessories and subsystems.

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.

An improved steam engine is provided for operating on a recirculation of superheated air and steam. A gas turbine is including having a first intake, a first discharge and a power output shaft, said power output shaft providing rotation power output generated from a change in entropy of the gas through the turbine. A power turbine superheats the gas discharge and includes a turbocharger in operational communication with an electric DC motor, and a compressor mechanically driven by the turbocharger. The discharge from the compressor forms the turbine steam intake. A water injection system may be further provided for adding steam to the air recirculating circuit. A drive motor operatively coupled to the turbine may be used for startup to bring the turbine up to operational rotation speeds. A DC generator operatively coupled to recharge a battery driving the drive motor or for providing electrical power output.

An improved steam engine is provided for operating on a recirculation of superheated air and steam. A gas turbine is including having a first intake, a first discharge and a power output shaft, said power output shaft providing rotation power output generated from a change in entropy of the gas through the turbine. A power turbine superheats the gas discharge and includes a turbocharger in operational communication with an electric DC motor, and a compressor mechanically driven by the turbocharger. The discharge from the compressor forms the turbine steam intake. A water injection system may be further provided for adding steam to the air recirculating circuit. A drive motor operatively coupled to the turbine may be used for startup to bring the turbine up to operational rotation speeds. A DC generator operatively coupled to recharge a battery driving the drive motor or for providing electrical power output.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly. The engine assembly may include a first monolithic body segment and a plurality of second monolithic body segments directly coupled or directly couplable to the first monolithic body segment. The first monolithic body segment may define a combustion chamber and a recirculation pathway in fluid communication with the combustion chamber. The recirculation pathway may be configured to recirculate combustion gas through the combustion chamber. The plurality of second monolithic body segments may respectively define at least a portion of a piston chamber and a plurality of working-fluid pathways fluidly communicating with the piston chamber.