Turbine system with lift-producing blades

A turbine system comprising:

• a shaft configured to rotate about a rotational axis;
• a plurality of blades coupled to the shaft, wherein the blades are oriented with the width (chord) axis of the blades aligned in a radial direction away from the rotational axis, and wherein the blades are configured to provide lift according to the Bernoulli principle resulting from lower pressure on convex first blade sides of the blades exposed to air flow than on second blade sides of the blades exposed to the air flow, when fluid passes on both sides of the blades, the lift provided in the direction of rotation through portions of the rotation of the blades about the rotational axis on both the windward and leeward sides of the rotational axis;
• mounting formations which attach the blades to the shaft and suspend the blades away from the shaft, with air flow passages defined between the shaft and the blades;
• and
• an air flow director configured to expose the blades to air flow through a first part of rotation of the blades about the rotational axis, and to block air flow to the blades through a second part of the rotation of the blades about the rotational axis;
• wherein the air flow director is configured and oriented to direct the air flow in part through the air flow passages defined between the shaft and the blades;
• and
• wherein the air flow director has a convex outer surface located on the leeward side of the blades, with the convex outer surface exposed to the air flow;
• and
• wherein the air flow director with the convex outer surface exposed to the air flow on the leeward side of the rotational axis is configured so that when the blades are moving on the leeward side of the rotational axis, a straight line perpendicular to the chord line of any blade drawn from the chord line away from the convex surface of such blades will not intersect the convex surface of the air flow director on the leeward side of the rotational axis.