Embedded Actuators in Composite Airfoils

Abstract

An airfoil having active actuators and at least one morphing area allowing shape change of the airfoil and further allowing for optimization of the airfoil shape at more than one operating condition.

What we claim is: 
     
         1 . An airfoil, comprising:
 a root which is connectable to a rotating rotor assembly;   an airfoil portion connected to said root, said airfoil having a leading edge, a trailing edge and an outer edge opposite said root;   said airfoil portion being formed of composite material and having a morphable area which changes shape by actuation of an active actuator.   
     
     
         2 . The airfoil of  claim 1  wherein said active actuator is a piezoelectric actuator. 
     
     
         3 . The airfoil of  claim 2  wherein said piezoelectric actuator varies camber by application of voltage. 
     
     
         4 . The airfoil of  claim 1  further comprising a passive actuator is a shape memory alloy. 
     
     
         5 . The airfoil of  claim 1  wherein said airfoil portion is formed of multiple layers of material. 
     
     
         6 . The airfoil of  claim 5  wherein said active actuator is located adjacent an outer layer of said material. 
     
     
         7 . The airfoil of  claim 1  wherein said active actuator is located adjacent said trailing edge. 
     
     
         8 . The airfoil of  claim 1  wherein said composite material is formed of multiple layers of varying moduli. 
     
     
         9 . The airfoil of  claim 1  further comprising first and second actuators. 
     
     
         10 . The airfoil of  claim 9  further comprising a shape memory alloy and piezoelectric fiber embedded in said airfoil. 
     
     
         11 . The airfoil of  claim 1  wherein said morphable area includes chordwise fibers. 
     
     
         12 . The airfoil of  claim 1  wherein said morphable area includes sparwise fibers. 
     
     
         13 . The airfoil of  claim 1  wherein said morphable area includes oblique fibers. 
     
     
         14 . The airfoil of  claim 1  wherein said airfoil further comprises an asymmetric layering of composite fibers. 
     
     
         15 . An airfoil, comprising:
 an airfoil portion having a leading edge and a trailing edge;   an outer edge spaced from a radially inner portion of said airfoil portion, said outer edge extending between said leading and trailing edge;   a morphable portion disposed along said airfoil which is shape changeable;   an active actuator disposed within said morphable portion to change the shape of said morphable portion by application of voltage to said active actuator.   
     
     
         16 . The airfoil of  claim 15  further comprising a root at said radially inner portion of said airfoil portion. 
     
     
         17 . The airfoil of  claim 15 , said active actuator changing camber of said airfoil. 
     
     
         18 . The airfoil of  claim 17  further comprising a passive actuator. 
     
     
         19 . The airfoil of  claim 18  wherein said passive actuator is one of a shape metal alloy or an asymmetric layered material. 
     
     
         20 . An airfoil having a changeable shape, comprising:
 an airfoil portion having a leading edge and a trailing edge and formed of a plurality of layers of composite material;   a morphable portion located between a radially inner end and a radially outer end of said airfoil portion and between said leading edge and said trailing edge;   said airfoil portion having an active actuator located within said morphable portion, said active actuator receiving a voltage input to vary a shape to said morphable portion; and,   wherein said composite material and material of said morphable portion are at least partially differing materials.