Abstract: Underwater vehicles capable of self-propulsion are described. An underwater vehicle includes a cross-flow turbine including two or more foils spaced apart from a main shaft. The foils have a pitch that is adjustable under control of a pitch control mechanism. The underwater vehicle also includes a frame supporting the main shaft. The frame enables rotation of the cross-flow turbine. The underwater vehicle additionally includes a generator-motor set including rotor and stator elements. The rotor element is in rotary communication with the main shaft.

Abstract: Underwater vehicles capable of self-propulsion are described. An underwater vehicle includes a cross-flow turbine including two or more foils spaced apart from a main shaft. The foils have a pitch that is adjustable under control of a pitch control mechanism. The underwater vehicle also includes a frame supporting the main shaft. The frame enables rotation of the cross-flow turbine. The underwater vehicle additionally includes a generator-motor set including rotor and stator elements. The rotor element is in rotary communication with the main shaft.

Abstract: The present invention is directed to a turbine comprising a pair of opposing end discs concentrically aligned with a central axis of the turbine and a plurality of blades extending between the end discs. At least one end discs is adapted for engaging with a generator for generating power. The plurality of blades rotates in a single direction when exposed to fluid flow and thereby rotates the pair of opposing end discs. The plurality of blades are interconnected by at least one faired ring oriented parallel to the pair of opposing end discs and intersecting the plurality of blades, wherein the at least one faired ring is in concentric alignment with the central axis. The present invention further comprises a method for generating power comprising engaging the turbine with a generator to create a turbine generator unit and deploying the turbine generator unit within a fluid flow.

Abstract: The present invention is directed to a turbine comprising a pair of opposing end discs concentrically aligned with a central axis of the turbine and a plurality of blades extending between the end discs. At least one end discs is adapted for engaging with a generator for generating power. The plurality of blades rotates in a single direction when exposed to fluid flow and thereby rotates the pair of opposing end discs. The plurality of blades are interconnected by at least one faired ring oriented parallel to the pair of opposing end discs and intersecting the plurality of blades, wherein the at least one faired ring is in concentric alignment with the central axis. The present invention further comprises a method for generating power comprising engaging the turbine with a generator to create a turbine generator unit and deploying the turbine generator unit within a fluid flow.

Abstract: The present invention provides a connector arrangement operative to connect a prime mover driven alternator to an alternating current circuit with an existing alternating current. For example, the connector arrangement may be used to connect an alternator driven by a Stirling engine to an alternating current mains electricity supply. The connector arrangement includes a circuit with an adjustable resonant frequency, adjustable between a first resonant frequency tuned to an initial operating frequency of the prime mover and a second resonant frequency detuned to the initial operating frequency. This adjustable resonant frequency is beneficial as it allows operation to be tailored to the exact operating conditions of the prime mover that is likely to have its own resonant frequency that may vary according to its operating condition.

Abstract: A microminiature Stirling cycle engine or cooler is formed utilizing semiconductor, planar processing techniques. Such a Stirling cycle thermomechanical transducer has silicon end plates and an intermediate regenerator. The end plates are formed with diaphragms and backspaces, one end plate forming the expansion end and the opposite end plate forming the compression end, with the regenerator bonded in between. A control circuit apparatus is linked to the diaphragms for controlling the amplitude, phase and frequency of their deflections. The control circuit apparatus is adapted to operate the transducer above 500 Hz and the passages and the workspace, including those within the regenerator, expansion space and compression space, are sufficiently narrow to provide a characteristic Wolmersley number, which is characteristic of the irreversibilities generated by the oscillating flow of the working fluid in the workspace, below substantially 5 at the operating frequency above 500 Hz.

Abstract: A microminiature Stirling cycle engine or cooler is formed utilizing semiconductor, planar processing techniques. Such a Stirling cycle thermomechanical transducer has silicon end plates and an intermediate regenerator. The end plates are formed with diaphragms and backspaces, one end plate forming the expansion end and the opposite end plate forming the compression end, with the regenerator bonded in between. A control circuit apparatus is linked to the diaphragms for controlling the amplitude, phase and frequency of their deflections. The control circuit apparatus is adapted to operate the transducer above 500 Hz and the passages and the workspace, including those within the regenerator, expansion space and compression space, are sufficiently narrow to provide a characteristic Wolmersley number, which is characteristic of the irreversibilities generated by the oscillating flow of the working fluid in the workspace, below substantially 5 at the operating frequency above 500 Hz.

Abstract: A piston centering system for a free piston machine. The invention uses a centering passageway which is in communication between a work space and a second space which spaces are formed in a housing and are separated by a piston which reciprocates in a cylinder in the housing. The centering passageway has a valve, such as a spool valve formed in the piston and cylinder or a center post, the valve opening in response to the piston being near the center of the opposite limits of its reciprocation. The improvement is the inclusion of a pressure responsive, one way valve interposed in the passageway. The one way valve is oriented to permit the passage of the working gas through the passageway from one space to the other in a direction opposite to a net leakage flow from one space to the other through the annular gap between the piston and cylinder and to prevent substantial flow through the passageway in the reverse direction.