Reconfiguration control system for an aircraft wing

#The present invention relates generally to aerodynamics and, more particularly, to a reconfiguration control system for optimizing the spanwise lift distribution on a blended wing-body aircraft by reconfiguring the deflection of trailing edge control surfaces.

#There are primarily two types of aircraft configurations: the more common configuration which includes a tail section comprised of vertical and horizontal stabilizers located at the aft end of a tubular fuselage; and the tailless configuration. As to tailless aircraft, there are two sub-types: a first type which has no central body, commonly known as a “flying wing,” and a second type having a central body which is blended into laterally extending wings.

#Tailless aircraft possess the advantages of inherently lower weight and drag than a comparatively sized conventional aircraft having a fuselage and tail section. Several features of tailless aircraft effect these advantages. First, the need to enclose payloads in the wing results in thicker airfoil sections that are efficient at resisting bending loads, thereby lowering the necessary structural weight. Second, payload and fuel are distributed in the spanwise direction, which shifts the weight closer to where the lift is generated, thus reducing the structural loads that must be carried. Third, elimination of horizontal and vertical tail surfaces reduces the aircraft's wetted area and thus reduces parasite (skin friction) drag. These advantages have enticed aircraft designers to consider tailless configurations for a variety of military and commercial applications.

#These and various other features and advantages of the present invention will be readily understood with reference to the following detailed description read conjunction with the attached drawings, in which:

#FIG. 1 is a schematic drawing of a conventional aircraft of the prior art having a tubular fuselage and an appended tail section which includes a vertical stabilizer and a horizontal stabilizer;

#FIG. 2 is a schematic drawing of a tailless aircraft of the prior art;

#An exemplary conventional aircraft 20 having a tail section is schematically depicted in FIG. 1. Aircraft 20 includes tubular fuselage 21, wing 23, horizontal stabilizer 25, and vertical stabilizer 27. When loaded, aircraft 20 has center of gravity 29. Horizontal stabilizer 25 controls the rotation of aircraft 20 about the pitch axis passing through center of gravity 29. Vertical stabilizer 27 controls the rotation of aircraft 20 about the vertical, or “yaw,” axis passing through center of gravity 29.

#The vector L represents the lift generated by wing 23. The additional lift generated by fuselage 21 is small in comparison to the lift generated by wing 23, and will be ignored herein. The vector I represents the lift generated by horizontal stabilizer 25 and is adjusted as necessary to stabilize the pitch moments of the aircraft. The presence of horizontal stabilizer 25 and vertical stabilizer 27 contributes a significant component to the total drag coefficient for aircraft 20.

#Another drawback inherent to aircraft 20 is the weight of fuselage 21. Fuselage 21 is present primarily to carry payload. Secondary functions of the fuselage are to provide a pitch moment arm of sufficient length to allow the pitch rotation of aircraft 20 to be controlled by the lift I generated by horizontal stabilizer 25 and to provide a yaw moment arm of sufficient length to allow the yaw rotation of aircraft 20 to be controlled by the force vector generated by vertical stabilizer 27.