| 摘要 |
A tidal or river turbine 2 has a helical rotor 3 arranged with its rotation axis inclined to the direction of water flow W. The helical rotor has a blade 10 comprising a first, convex surface 12, a second, concave surface 13 and a free, distal edge E where the first surface and the second surface meet. The curvature of the second surface, when viewed in a plane orthogonal to the rotational axis, is such that a maximum depth Dmax of the second surface, when measured from a straight line intersecting the rotational axis and the distal edge, is at least 35% of the distance between the rotational axis and the distal edge. |
