Minimisation of Shape Deviation Between an Inflatable Aerofoil and a Target Areofoil Profile

Abstract

The use of inflatable wings for unmanned aerial vehicles over their fixed-winged counterparts has many advantages. However, there are difficulties associated with predicting the profile of the inflatable wing, which makes achieving a desirable aerofoil profile non-trivial. This research aimed to formulate a design methodology which would determine the uninflated geometry for an inflatable aerofoil profile, accurately fitting that of a target or prescribed profile. The aspects omitted from the scope of this work includes the aerodynamic performance and stiffness of the inflated aerofoils. The resulting uninflated geometry is suitable to construct a physical model. The methodology proposed incorporates numerical shape optimisation on finite element models. A series of structured numerical experiments determine robusticity of the established methodology by altering the thickness of the target aerofoil profile and increasing its complexity. For each case, the methodology successfully satisfied its aim, producing accurate fits between the inflated numerical model and the target aerofoil profile. When validated, the inflated shape of the numerical model proved to predict that of its corresponding physical model accurately for both simple and more complex geometries.