Highly Extensible Skin of a Variable Geometry Wing Leading Edge of a High-Performance Sailplane

Abstract

In 2011 the Akaflieg Munchen e.V. began research on a variable geometry wing of a sailplane. The advantage of a leading edge with a variable camber was investigated by Wießmeier on the basis of the ASW 27 airfoil. The results show a great potential of achieving a higher wing loading and a higher cruising speed along with excellent low-speed flight characteristics. Subsequently, different designs of the technical implementation of a variable geometry wing leading edge are considered. This paper presents the results of a study whose principal aim is to design and analyse a highly extensible section of a variable geometry wing leading edge. This section is designed as a sandwich, composed of an accordion honeycomb core with elastomeric top layers. It has a high bending stiffness as well as a high extensibility into one direction, allowing for the wing leading edge to morph downward.