Investigation of a Variable Camber Morphing Airfoil via SMA Wire and Corrugated Structures

This study proposes a novel design concept of SMA wire technology that is applied to an Eppler E397 morphing airfoil. The study suggests replacing a conventional flap like structure which is typically located at 75% chord with a smooth geometry morphing flap positioned at 65% chord. The morphing flap is assumed to be actuated by a shape memory alloy wire and compliant structure mechanism instead of a conventional hydraulic system. The design concept is studied and verified by conducting a finite element analysis to check the structural integrity. A parametric study was then conducted on the number and position of the wire within the airfoil to investigate the amount of downward deflection that can result from the proposed mechanism. As a result, the amount of deflection angle increased directly as the position of the wire approached the upper surface of the airfoil (up to 8.2 degrees). In addition, aerodynamic parameters resulting from the deflected geometries were evaluated using Athena vortex lattice methods (AVL) and then compared to a conventional airfoil with hinged flap-like-structure. The results showcased an increase in lift coefficient, a decrease in drag coefficient, and enhanced aerodynamic efficiency of the morphing flap-like-structure.