FLIGHT DYNAMIC SIMULATION ASSESSMENT OF A MORPHABLE HYPER-ELLIPTIC CAMBERED SPAN WINGED CONFIGURATION

As part of the Morphing Project in the Aerospace Vehicle Systems Technology Program, NASA is conducting biomimetics research aimed at the study of natural morphologies that may prove beneficial for advanced flight systems. Wind tunnel tests were conducted in 2002 to compare three biologically inspired wing designs with a planar elliptic wing; theoretically considered the best planar configuration for the least induced drag. All wings had the same aspect ratio and wing span. One of the wings, referred to as a Hyper-Elliptic Cambered Span (HECS) due to its continuously varying span-wise curvature, demonstrated that although it had nearly a 10 percent increase in surface area it provided a lift-to-drag increase of as much as 15 percent. Because of its beneficial aerodynamic properties, the Hyper-Elliptic Cambered Span wing has been chosen as a focus concept for wing morphing (continuous physical shape change) research. To be of potential use on a vehicle, morphing concepts must allow for adequate stability and control properties. Flight control designs must be validated in simulation and eventually in flight. This paper presents the development of a non-linear, CFDbased, dynamic vehicle simulation incorporating a morphable Hyper-Elliptic Cambered Span wing. This vehicle utilizes a continuous (hingeless, gapless) morphable panel along the trailing edge of the wing and a continuous moveable wing tip for pitch, roll, and yaw control. The simulation is used as the basis for the assessment of vehicle stability and control characteristics and the viability of using wing morphing for primary maneuver control. Linear state space models of the vehicle associated with typical trimmed level flight conditions are also presented.