Abstract: A ventilator comprising an air blower; a casing comprising a first wall and a second wall configured to house the air blower centrally and to define a radially decreasing volume therebetween, a circumferential gap between the first wall and the second wall configured to allow a high velocity air stream to exit and to spiral in a direction away from a structure to which the ventilator is configured to be mounted, and a central opening in the second wall configured as a suction inlet of the air blower; and a flow amplifier adjacent the casing and configured to amplify air flow through an air flow passage defined between the flow amplifier and the second wall of the casing.

Abstract: A ventilator comprising an air blower; a casing comprising a first wall and a second wall configured to house the air blower centrally and to define a radially decreasing volume therebetween, a circumferential gap between the first wall and the second wall configured to allow a high velocity air stream to exit and to spiral in a direction away from a structure to which the ventilator is configured to be mounted, and a central opening in the second wall configured as a suction inlet of the air blower; and a flow amplifier adjacent the casing and configured to amplify air flow through an air flow passage defined between the flow amplifier and the second wall of the casing.

Abstract: A turbine assembly and a system for extracting tidal energy are disclosed. The turbine assembly may include identical sections disposed in a stacked arrangement. Each section may be shaftless, energizable by a fluid flow to produce lift and is appropriately oriented at a phase shift to an adjacent section such that a relatively constant resultant torque output with small amplitude fluctuation is generated by rotation of the turbine assembly. The turbine assembly may be employed in conjunction with a velocity enhancing device having a housing with variable profile openings to enhance the torque output. The turbine assembly may further be employed in a floating barrage arrangement which is transportable.