Design and Aerodynamic Characteristics of a Span Morphing Wing

摘要

Flight vehicles are often designed to function around a primary operating point such as an efficient cruise or a highmaneuverability mode. Performance and efficiency deteriorate rapidly as the airplane moves towards other portions ofthe flight envelope. One solution to this quandary is to radically change the shape of the aircraft. This yields bothimproved efficiency and a larger flight envelope. This global shape change is an example of morphing aircraft . Oneconcept of morphing is the span morphing wing in which the wingspan is varied to accommodate multiple flightregimes. This type of design allows for at least two discreet modes of the aircraft. The original configuration, in whichthe extensible portion of the wing is fully retracted, yields a high speed dash mode. Fully extending the wing providesthe aircraft with a low speed mode tailored for fine tracking and loiter tasks. This paper discusses the design of a span morphing wing that permits a change in the aspect ratio while simultaneouslysupporting structural wing loads. The wing cross section is maintained by NACA 4412 rib sections . The span morphingwing was investigated in different configurations. The wing area and the aspect ratio of the span morphing wing increaseas the wings pan increases. Computational aerodynamics are used to estimate the performance and dynamiccharacteristics of each wing shape of this span morphing wing as its wingspan is changed. Results show that in order toobtain the same lift, the conventional wing requires a larger angle of attach(AOA) than that of the span morphingwing.The lift of the span morphing wing increases as the wing span ,Mach number and AOA increases.