Enhanced Range and Endurance Evaluation of a Camber Morphing Wing Aircraft

Abstract

Flight range, endurance, maneuverability, and agility are the key elements that determine an aircraft's performance. Both conventional and morphing wing aircraft have been well studied and estimated in all aspects of performance. When considering the performance of morphing aircraft, most works address aspects of the aerodynamical performance such as L and D as well as flight envelopes for flight dynamics and control perspectives. However, the actual benefits of adopting morphing technologies in practical aspects such as aircraft operation, mission planning, and sustainability have not been addressed so far. Thus, this paper addresses the practical aspect of the benefits when adopting a camber morphing wing aircraft. Identical geometrical and computational conditions were applied to an already-existing aircraft: the RQ-7a Shadow. The wing structure was switched between a fixed wing and a camber morphing wing to generate conventional and morphing wing geometries. The fixed-wing cases had varying flap deflection angles, and the camber morphing wing cases had varying camber rates from 4% to 8%. Once the CL values of the fixed and morphing wing cases were matched up to two significant figures, the CD and CL/CD were analyzed for these matching cases to calculate the flight endurance, range, and improvement. When NACA 6410 is adopted, a 17% improvement in flight range and endurance average was expected. In the case of NACA 8410, an average 60% improvement was expected.

Keywords: Reynolds number; camber morphing; conventional; fixed wing; flight endurance; flight range; morphing aircraft; single Re.

Figure 1

Flowchart of aircraft design and analysis cycle (image courtesy of J.T. Kim).

Figure 2

(a) $C_L$ and (b) $C_D$ plots of baseline NACA 2410 airfoil (Re = 778,179).

Figure 3

Matching L morphing (NACA 4410) and conventional airfoil plots (Re = 778,179): (a) $L$ plot; (b) D plot; (c) L/D; (d) endurance ratio.

Figure 3

Matching L morphing (NACA 4410) and conventional airfoil plots (Re = 778,179): (a) $L$ plot; (b) D plot; (c) L/D; (d) endurance ratio.

Figure 4

Matching $C_L$ morphing (NACA 6410) and conventional airfoil plots (Re = 778,179): (a)$C_L$; (b)$C_D$; (c)$C_L/C_D$; (d) endurance ratio.

Figure 5

Matching $C_L$ morphing (NACA 8410) and conventional airfoil plots (Re = 778,179): (a)$C_L$; (b)$C_D$; (c)$C_L/C_D$; (d) endurance ratio.