Propulsion can be achieved without expelling matter by using a non-inertial subsystem to generate substantial internal Coriolis recoil forces that supply propulsion. A unique subsystem has been designed in which mass (fluids) is discretely injected radially into a non-inertial system comprising arrays of spinning radially-oriented vanes mounted on thin discs forming a stacked array of rectangular cross section tubes lock onto a common spinning shaft. In the preferred embodiment of the invention, the mass (fluid) is input into the tubes at the circumference of the spinning system by radially injecting the fluid at high velocity onto one tube at a time at the outer end of the tubes. The mass is then centrifugally slowed as it travels in toward the axis and leaves the system at a very low velocity near the axis of rotation. During the retarded motion, the tubes experience a continuous Coriolis recoil force that is opposite the rotation direction at each instantaneous location to which the mass has been centrifugally decelerated. The resultant non-linear Coriolis reaction or recoil is constrained to acting through the axis of rotation of the spinning discs by keeping the rotation rate constant. All Coriolis recoil forces act through the center of rotation no matter where in a tube a mass has been propelled as long as the rotation rate is held constant. The integrated reactive Coriolis force from each injected fluid mass is non-linear and orders of magnitude larger than occurs in commercial symmetric rotating-vane systems. The net integrated reactive force acting on the axis of rotation of the subsystem produces a propulsive force. The injected and retarded fluids are captured near the rotation axis and recirculated back to the input injectors. By conserving the reaction mass, a closed propulsion system can be designed that only depends on the availability of power from a variety of sources.

A method for using a pressure exchanger to reduce flow as a choke that includes receiving a flow of high pressure fluid at the pressure exchanger, filling a chamber of the pressure exchanger with high pressure fluid, and discharging a portion of the fluid in the chamber at a low pressure.

A hydroelectric power generation system includes: a generator driven by the hydraulic turbine; a head adjuster adjusting an effective head of the hydraulic turbine; and a controller cooperatively executing: flow rate control for controlling the generator such that a flow rate in the hydraulic turbine is brought close to a target flow rate; and head adjusting control for adjusting the effective head of the hydraulic turbine using the head adjuster such that the effective head of the hydraulic turbine falls within a first range.

A method and apparatus using atmospheric pressure and vacuum force to generate electricity performs coordinated operations of normally open (NO) valves and normally closed (NC) valves to repeatedly push water through an upward pipeline to a first vacuum chamber and let the water flow down by gravity to strike the water wheel of a hydraulic power generator installed in a second vacuum chamber to generate electricity. The method and the apparatus is not affected by local climates or geographical locations and may be installed and applied almost anywhere.

A method and apparatus using atmospheric pressure and vacuum force to generate electricity performs coordinated operations of normally open (NO) valves and normally closed (NC) valves to repeatedly push water through an upward pipeline to a first vacuum chamber and let the water flow down by gravity to strike the water wheel of a hydraulic power generator installed in a second vacuum chamber to generate electricity. The method and the apparatus is not affected by local climates or geographical locations and may be installed and applied almost anywhere.

The present invention provides improvement of the operation of a wave energy system by use of a method for predictive control (COM) of the converter machine that maximizes the energy generated by considering the energy conversion efficiency (MOD ENE) and a wave prediction (PRED). Furthermore, the method according to the invention determines the optimal control by minimizing an objective function weighted and discretized by the trapezoidal rule.

The present invention provides improvement of the operation of a wave energy system by use of a method for predictive control (COM) of the converter machine that maximizes the energy generated by considering the energy conversion efficiency (MOD ENE) and a wave prediction (PRED). Furthermore, the method according to the invention determines the optimal control by minimizing an objective function weighted and discretized by the trapezoidal rule.

A hydraulic power generation system is provided with a control unit which controls the power supply circuit to perform a normal operation of supplying power from the power system to a predetermined electric device provided at the water channel and an autonomous operation of supplying the power generated by the electric generator to the electric device. The control unit executes the autonomous operation when the power system fails.

A hydraulic power generation system is provided with a control unit which controls the power supply circuit to perform a normal operation of supplying power from the power system to a predetermined electric device provided at the water channel and an autonomous operation of supplying the power generated by the electric generator to the electric device. The control unit executes the autonomous operation when the power system fails.

A hydroelectric turbine installation includes a turbine, a water passage located upstream, a draft tube, a controller that controls operation conditions, a device for introducing oxygen-containing gas into water passing through the installation, a device for injecting water into the draft tube, and a device for controlling a flowrate of the water injected into the draft tube. The device for controlling the flowrate includes a control unit and a valve. The control-unit is configured to control the flowrate of the water injected into the draft tube in a way that the flowrate is a function of the operation conditions of the turbine. The flowrate set by the control unit at an operation condition of the turbine corresponding to an optimal efficiency point of the turbine is higher than a flowrate set by the control-unit at one or more other operation conditions of the turbine that do not correspond to an optimal efficiency point.