Airfoil or rotor blade having a continuous trailing edge flap

Abstract

Embodiments of the present invention include various airfoils constructions, such as airfoils and rotor blades having a continuous trailing-edge flap. According to an embodiment, an airfoil is comprised of a load-bearing structure in the forward portion of the airfoil; a skin to maintain the airfoil shape; a tapered composite structure having one or more actuators extending from the load-bearing structure toward the trailing edge, and joining the skin in the vicinity of the trailing edge; and a core extending from the load-bearing structure connecting the tapered composite structure to the load-bearing structure. In this airfoil, the tapered composite structure tapers from being relatively thick near the core to being relatively thin near the trailing edge. And the one or more actuators are configured to deflect the trailing edge so as to deform the shape of the airfoil cross-section.

I claim: 
     
         1 . An airfoil comprising:
 a load-bearing structure in the forward portion of the airfoil;   a skin to maintain the airfoil shape;   a tapered composite structure having one or more actuators extending from the load-bearing structure toward the trailing edge, and joining the skin in the vicinity of the trailing edge, the one or more actuators being configured to deflect the trailing edge so as to deform the shape of the airfoil cross-section; and   a core extending from the load-bearing structure connecting the tapered composite structure to the load-bearing structure, wherein the tapered composite structure tapers from being relatively thick near the core to being relatively thin near the trailing edge.   
     
     
         2 . The airfoil of  claim 1 , wherein the skin is composed of one or more discrete flexible sections above and below the tapered composite structure. 
     
     
         3 . The airfoil of  claim 1 , wherein the load-bearing structure is composed of composite plies or an integral structure. 
     
     
         4 . The airfoil of  claim 1 , wherein the core comprises composite plies of the load-bearing structure extending rearward. 
     
     
         5 . The airfoil of  claim 1 , wherein the core comprises separate composite plies connected to the load-bearing structure. 
     
     
         6 . The airfoil of  claim 1 , wherein the core comprises a separate piece connected to the load-bearing structure. 
     
     
         7 . The airfoil of  claim 1 , wherein the core comprises an integral portion formed on the load-bearing structure. 
     
     
         8 . The airfoil of  claim 1 , further comprising honeycomb or foam cores, above and below, the tapered composite structure. 
     
     
         9 . The airfoil of  claim 1 , wherein the one or more actuators are bonded and/or attached via adhesive, glue, and/or fasteners. 
     
     
         10 . The airfoil of  claim 1 , wherein the one or more actuators are formed of multiple layers of the piezoelectric actuators connected together. 
     
     
         11 . The airfoil of  claim 10 , wherein the piezoelectric actuators are configured as a bimorph. 
     
     
         12 . The airfoil of  claim 1 , wherein two or more actuators are provided. 
     
     
         13 . The airfoil of  claim 12 , at least one actuator is provided at the top and the bottom of the tapered composite structure, respectively. 
     
     
         14 . The airfoil of  claim 1 , wherein the tapered composite structure is attached to top and bottom portions of the core, respectively. 
     
     
         15 . The airfoil of  claim 1 , wherein, near the core, the thickness of the tapered composite structure is approximately 2% of the chord length of the airfoil, and near the trailing edge, the thickness of the tapered composite structure is about 0.3% of the chord length. 
     
     
         16 . The airfoil of  claim 1 , wherein the taper of the tapered composite structure is linearly tapering. 
     
     
         17 . The airfoil of  claim 1 , wherein the degree of tapering at the top and bottom of the tapered composite structure is different. 
     
     
         18 . A helicopter or tiltrotor rotor blade comprising the airfoil of  claim 1 . 
     
     
         19 . A wind turbine blade comprising the airfoil of  claim 1 . 
     
     
         20 . An aerodynamic control surface comprising the airfoil of  claim 1 .