CPC F04D 29/368 (2013.01) [F03G 7/0614 (2021.08); F04D 19/002 (2013.01)] | 19 Claims |
1. An airfoil rotatable about an axis in a first circumferential direction to move air in a first axial direction, the airfoil comprising:
a root portion;
a tip portion; and
a clearance device formed of a shape memory alloy and disposed between the root portion and the tip portion, the clearance device movable between:
a first position wherein a clearance line is defined along a proximal point, a transition point, and a distal point and extends in a substantially straight direction along the proximal point, the transition point, and the distal point; and
a second position wherein the clearance line is interrupted at the transition point to define a proximal line between the proximal point and the transition point, a distal line between the distal point and the transition point, and a deflection angle between the proximal line and the distal line less than one hundred and eighty degrees;
wherein the clearance device comprises a tip intermediate portion, the tip intermediate portion disposed radially further than the transition point from the axis, wherein the tip portion comprises a tip overlapping portion, wherein the clearance device comprises a first clearance device overlapping portion, wherein the first clearance device overlapping portion overlaps the tip overlapping portion across a chord of the airfoil, and wherein the first clearance device overlapping portion extends across less than seventy-five percent (75%) of the airfoil.
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