United States of America As Represented by the Administrator of Nasa

The United States of America As Represented by the Administrator of the

Nhan Thanh Nguyen

John J Burken

Nicholas Bryan Cramer

Kelley Elizabeth Hashemi

Eric B Ting

Curtis E Hanson

Eric Bi-Wen Ting

Kevin Wayne Reynolds

Juntao Xiong

An anti-phase rotor system for an aircraft may include at least one rotor with at least two rotor blades. The aerodynamic profile of these two blades may be selected to create counteracting blade vortices to break up harmonic reinforcement due to the rotor blade passage. The aerodynamic profile may create a non-planar motion of one or more rotor blade passages, whereby the individual rotor blades are not co-planar during the rotation of said rotor. The rotor system may include a duct, which may include stationary vanes or struts configured in a manner so as to break up harmonic excitation to the rotor. The interior area of the duct at the area of the blade rotation may be designed in a manner so as to create a destructive rotor blade tip vortex interference.

Anti-phase noise suppression rotor technologies

Processes for real-time drag optimization control for aeroelastic wing structures are disclosed. Adaptive reconfiguration of aircraft control surfaces by an online real-time drag optimization control approach to reduce or minimize drag may reduce the amount of fuel that is consumed by the aircraft during flight. The input data may be obtained from sensor information pertaining to the wing deflection and aircraft state information. The optimization approach may compute an optimal solution of the distributed flight control surface deflections that are integrated in a flight path angle flight control system.

Real-time drag optimization control framework

A flight control system for an aircraft having a multi-functional flight control surface. The aircraft has at least one multi-functional flight control surface formed by a sequence of flaps. The shape of each multi-functional flight control surface may be configured by a flight control to simultaneously adjust a trajectory of the aircraft in two or more of a pitch direction, a roll direction, and a yaw direction. The flight control for operating said the multi-functional flight control surface responds to both pilot commands and machine-generated commands. The machine-generated commands configure the shape of the surface of each multi-functional flight control surface in real-time based, at least in part, upon a set of flight objectives comprising: (a) minimizing drag of the aircraft, (b) aeroelastic modal suppression for the aircraft, and (c) maneuver load alleviation in the aircraft.

Flight control system for aircraft having multi-functional flight control surface

There is provided an aerodynamic control apparatus for an air vehicle comprising a flap system including a first spanwise flap segment to be arranged on a first side of an air vehicle, a second spanwise flap segment to be arranged on the first side of the air vehicle, and a controller to actuate the first spanwise flap segment to a first flap deflection and the second spanwise flap segment to a second flap deflection, wherein the first spanwise flap segment at the first flap deflection and the second spanwise flap segment at the second flap deflection form a piecewise continuous trailing edge.

Variable camber continuous aerodynamic control surfaces and methods for active wing shaping control

An aircraft has wings configured to twist during flight. Inboard and outboard propulsion devices, such as turbofans or other propulsors, are connected to each wing, and are spaced along the wing span. A flight controller independently controls thrust of the inboard and outboard propulsion devices to significantly change flight dynamics, including changing thrust of outboard propulsion devices to twist the wing, and to differentially apply thrust on each wing to change yaw and other aspects of the aircraft during various stages of a flight mission. One or more generators can be positioned upon the wing to provide power for propulsion devices on the same wing, and on an opposite wing.

Aeroelastic wing shaping using distributed propulsion

Disclosed is a novel adaptive control method and system called optimal control modification with normalization and covariance adjustment. The invention addresses specifically to current challenges with adaptive control in these areas: 1) persistent excitation, 2) complex nonlinear input-output mapping, 3) large inputs and persistent learning, and 4) the lack of stability analysis tools for certification. The invention has been subject to many simulations and flight testing. The results substantiate the effectiveness of the invention and demonstrate the technical feasibility for use in modern aircraft flight control systems.

Control systems with normalized and covariance adaptation by optimal control modification

An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.

A new blading system for controlling the structural vibrations in axial-flow compressors, turbines, or fans, as in aircraft engines and like turbomachines including a stator disc and a rotor disc is presented. The rotor disc defines several radial hubs that retain the rotor blading systems. Each blading system includes a blade formed of an airfoil, and a root attachment which is dimensioned to fit within, and to engage a corresponding hub. Viscoelastic dampers are selectively applied to the outer surfaces of the root attachment on which compressive or shear forces are likely to develop, intermediate the root attachment and the hub, for compression therebetween upon rotation of the rotor disc, in order to dampen structural vibrations. One advantage presented by the viscoelastic dampers lies in its simplicity, efficiency, cost effectiveness, and its ability to be retrofitted into existing turbomachines with minor surface treatment of the root attachments. Furthermore, since the dampers are not exposed to the inflowing airstream, they do not affect the aerodynamic performance of the turbomachine. Another feature of the damping system is that it provides a significant source of damping to minimize destructive structural vibrations, thereby increasing the durability of the turbomachine, and reducing acoustic noise accompanying high amplitude vibrations.

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Santa Clara, CA, United States of America

Nhan Thanh Nguyen