Feasibility of FishBAC Morphing Camber Technology in Fixed Wing UAV applications

Abstract

The Fish Bone Active Camber (FishBAC) concept is a compliant camber morphing mechanism mounted at the trailing edge of the wing. FishBAC uses its compliant spine to deflect wing trailing edge geometry in a continuous fashion, altering the camber. This thesis assesses what potential performance benefits the FishBAC could bring to fixed wing unmanned aerial vehicles (UAVs). To investigate the problem thoroughly, 10 representative aircraft were studied, with masses ranging between 10 kg and 100 kg. These UAV geometries have been created using a consistent set of sizing tools and design trends based on existing UAVs, to ensure consistent results.
Throughout this study, a framework of low to medium fidelity methods was employed to calculate range differences between morphing and non-morphing UAVs. Aerodynamics was assessed using Xfoil for 2D viscous airfoil analysis, 3D Vortex-Lattice Method for wing and empennage aerodynamics, and a set of empirical and analytical methods to account for the fuselage and trim drag. FishBAC mass estimation is derived from maximum torque required for target morphing deformations, which is the main mass scaling factor. The combination of these methods within a unified analysis framework allowed for calculating range of each aircraft in morphing and non-morphing configurations.
The results indicate that a maximum range improvement for the UAVs considered in this study can be as much as 9%, for airspeeds approaching Vmax. For lower airspeeds, however, the improvement is more moderate. For airspeeds below Vcruise the addition of the morphing system led to a reduction in range. Using this framework, the FishBAC mass as a percentage of aircraft mean mass was found to range between 4-6%. Larger and faster flying platforms benefited from greater overall range improvement and suffered lower percentage mass penalty. All UAVs with mean mass less than 40kg yielded very similar range improvement results.

Date of Award	23 Jan 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Ben K S Woods (Supervisor) & Thomas C S Rendall (Supervisor)