Structure and method for a flexible trailing edge projection of an airfoil

A structure adapted to traverse a fluid environment, the structure comprising:

• an elongate body having a length defined by a root to a wingtip, and a width defined by a leading edge to a trailing edge, the elongate body traversing a fluid;
• a plurality of flexible projections, each of the flexible projections of the plurality of flexible projections having two peaks, a secondary trough between the two peaks and a primary trough between adjacent projections, and coupled to a respective position along the trailing edge and extending from a lowest point of the primary trough to a highest point of the two peaks to define a length of the flexible projection within the plurality of flexible projections;
• a pressure side extending along a chord length of the elongate body from the leading edge to the trailing edge;
• a suction side extending along the chord length of the elongate body from the leading edge to the trailing edge and opposing the pressure side, the pressure side and suction side generating a local median fluid pressure vector at the trailing edge;
• wherein the plurality of flexible projections bend to form a curvature extending from the lowest point of the primary trough to the highest point of the two peaks which conforms to the local median fluid pressure vector at the trailing edge of the elongate body and directs mixing of the fluid within the primary and secondary trough;
• and
• wherein the following condition is true for the plurality of flexible projections:
• k
• p
• L
• p
• 4
• >
• k
• b
• L
• b
• 4
• where kp is the stiffness of the flexible projection, Lp is the length of the flexible projection, kb is a stiffness of the elongate body, and Lb is the chord length of the elongate body, such that a lowest resonant frequency of the plurality of flexible projections is above a lowest resonant frequency of the elongate body.