Horizontal-axis hydrokinetic water turbine system

A hydrokinetic water turbine system configured to be placed in a flowing stream of water, said water turbine system comprising, in combination:

• a substantially rectangular and open frame structure;
• a shaft supported by the frame structure to rotate about a horizontally-disposed central axis of the shaft;
• a rotor secured to the shaft and having a first plurality of spaced-apart blades extending parallel to the central axis of the shaft and circumferentially spaced-apart about the shaft and a second plurality of spaced-apart blades extending parallel to the central axis of the shaft and circumferentially spaced-apart about the shaft so that the flowing stream of water revolves the rotor about the central axis of the shaft;
• wherein the first and second plurality of blades are each rigidly secured to prevent relative movement between the blades;
• wherein the first and second plurality blades are each straight in the longitudinal direction and have a hydrofoil shape in cross section configured to generate lift and rotate the rotor about the horizontally disposed central axis as the flowing stream of water passes around the hydrofoil shape;
• wherein the second plurality of blades is spaced apart from the first plurality of blades in the longitudinal direction and offset from the first plurality of blades so that the second plurality of blades is circumferentially located between the first plurality of blades for smooth rotation of the rotor;
• wherein the first and second plurality of blades are hollow extrusions with internal ribs between hollow cavities and the hollow cavities are filled with a material having a weight less than a weight of a material forming the extrusions;
• and
• wherein the frame structure comprises frame members adapted to reduce the coefficient of drag of the frame structure.

A hydrokinetic water turbine system configured to be placed in a flowing stream of water, said water turbine system comprising, in combination:

• a first hydrokinetic assembly comprising:
• a frame structure;
• a shaft supported by the frame structure to rotate about a horizontally-disposed central axis of the shaft;
• a rotor secured to the shaft and having a first plurality of spaced-apart blades extending parallel to the central axis of the shaft and circumferentially spaced-apart about the shaft and a second plurality of spaced-apart blades extending parallel to the central axis of the shaft and circumferentially spaced-apart about the shaft so that the flowing stream of water revolves the rotor about the central axis of the shaft;
• wherein the first and second plurality of blades are each rigidly secured to prevent relative movement between the blades;
• wherein the first and second plurality blades are each straight in the longitudinal direction and have a hydrofoil shape in cross section configured, to generate lift and rotate the rotor about the horizontally disposed central axis as the flowing stream of water passes around the hydrofoil shape;
• wherein the second plurality of blades is spaced a art from the first plurality of blades in the longitudinal direction and offset from the first plurality of blades so that the second plurality of blades is circumferentially located between the first plurality of blades for smooth rotation of the rotor;
• and
• wherein the first and second plurality of blades are hollow extrusions with internal ribs between hollow cavities and the hollow cavities are filled with a material having a weight less than a weight of a material forming the extrusions;
• a second hydrokinetic assembly comprising:
• a frame structure;
• a shaft supported by the frame structure to rotate about a horizontally-disposed central axis of the shaft;
• a rotor secured to the shaft and having a third plurality of spaced-apart blades extending parallel to the central axis of the shaft and circumferentially spaced-apart about the shaft and a fourth plurality of spaced-apart blades extending parallel to the central axis of the shaft and circumferentially spaced-apart about the shaft so that the flowing stream of water revolves the rotor about the central axis of the shaft;
• wherein the third and fourth plurality of blades are each rigidly secured to prevent relative movement between the blades;
• wherein the third and fourth plurality blades are each straight in the longitudinal direction and have a hydrofoil shape in cross section configured to generate lift and rotate the rotor about the horizontally disposed central axis as the flowing stream of water passes around the hydrofoil shape;
• wherein the fourth plurality of blades is spaced apart from the third plurality of blade in the longitudinal direction and offset from the third plurality of blades so that the fourth plurality of blades is circumferentially located between the third plurality of blades for smooth rotation of the rotor;
• and
• wherein the third and fourth plurality of blades are hollow extrusions with internal ribs between hollow cavities and the hollow cavities are filled with a material having a weight less than a weight of a material forming the extrusions;
• wherein the shafts of the first and second hydrokinetic assemblies are coaxial and the rotors of the first and second hydrokinetic assemblies are adapted to rotate in opposite directions.