Experimental Slender Wing Model Design by the Application of Aeroelastic Scaling Laws

Abstract

Long-endurance, unmanned air vehicles (UAVs) usually employ high-aspect-ratio, flexible wings to reduce weight and power required to achieve extended flight operation. There are currently several advanced concept designs and prototypes that will sustain autonomous operations for months or even years. The increased wing flexibility can lead to large structural deflections for trimmed flight states. These large elastic deformations within the static equilibrium state of the vehicle can induce aeroelastic instabilities quite different from their rigid counterparts. Therefore, it is imperative to perform flutter analysis, which considers the trimmed, large amplitude deformed state as a reference condition. Considering the complexity of the system under investigation, the aeroelastic flutter analysis process usually includes an experimental test phase for verification purposes. In this respect, wind tunnel test models provide the opportunity to modify and calibrate theoretical models, through a process of model updating. This paper proposes the development of an experimental, aeroelastic, slender-wing model that can be designed using a scaling procedure. The model is based on a consistent, aeroelastic, beam-wise scheme, capable of simulating the unconventional aeroelastic behavior of flexible wings.