Multidisciplinary Design Optimization of a Morphing Wing for an Experimental UAV

Abstract

§The aim of this work is to design a morphing wing concept for a small unmanned aerial vehicle (UAV), in order to improve the vehicle’s performance over its intended speed range. The wing is designed using a multidisciplinary design optimization framework where an aerodynamic shape optimization code coupled with a structural morphing model environment is setup to obtain a set of optimal wing shapes for minimum drag at different flight speeds. The optimization procedure is described as well as structural modelling. The aerodynamic shape optimization code, which uses an inviscid/viscous 2-dimensional panel method formulation coupled with a non-linear lifting-line algorithm and an sequential quadratic programming (SQP) optimization algorithm is suitable for preliminary wing design optimization tasks, although its robustness still needs further improvements. The morphing concept, based on changes in wing planform shape and wing section shape achieved by extending spars and telescopic ribs, is explained in detail. Comparisons between initial wing performance, optimal morphing wing performance and the performance of the wing obtained as the coupled aerodynamic-structural solution are presented. Estimates for the performance enhancements achieved by the UAV when fitted with this new morphing wing are also included. Some conclusions on this concept are addressed with comments on the benefits and drawbacks of the morphing mechanism design.