摘要:
A vane assembly, particularly suitable for a transverse flow, or vertical axis, turbine or a propulsion device comprises: avane with at least one concavo-convex part that is mounted by a pivot about so that it is free to rotate about a pivot axis. The pivot may connect the vane to a rotor with an axis of rotation, the pivot axis being inclined to the concave face such that, as the rotor turns, the vane is free to rotate about the pivot axis between a first position in which the vane defines a high-drag configuration for retreating with a transverse fluid flow, and a second position in which the vane defines a reduced-drag configuration for advancing against the transverse fluid flow.