CPC F04D 29/34 (2013.01) [F01D 5/146 (2013.01); F04D 19/002 (2013.01)] | 14 Claims |
1. A blade assembly for a large dimension axial fan having a rotation axis, comprising:
a root structure intended to mechanically connect the blade assembly to a hub of the axial fan;
a blade comprising at least one radially inner portion and a radially outer portion, the radially outer portion of the blade having a simple airfoil and the radially inner portion of the blade having a composite airfoil comprising a fore semi-airfoil and an aft flap, wherein:
the semi-airfoil of the blade is assemblable with a predefined pitch angle with respect to the hub of the axial fan by means of the root structure;
the aft flap is mounted on the blade such that it can be fixed in a position comprised between a maximum deflection position and a minimum deflection position with respect to the pitch angle; and
between the fore semi-airfoil and the aft flap a channel is defined suitable for allowing a fluid flow from a face to a back of the composite airfoil.
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