Time-domain simulation for evaluating smart wing concepts for reducing gust loads

摘要

Abstract: A numerical simulation for evaluating methods of predicting and controlling the response of an elastic wing in an airstream is discussed. The technique employed interactively and simultaneously solves for the response in the time domain by considering the air, wing, and controller as elements of a single dynamical system. The method is very modular, allowing independent modifications to the aerodynamic, structural, or control subsystems and it is not restricted to periodic motions or simple geometries. To illustrate the technique, a High Altitude, Long Endurance aircraft wing is used. The wing is modeled structurally as a linear Euler-Bernoulli beam that includes dynamic coupling between the bending and torsional oscillations. It is discretized via finite elements. The general, nonlinear, unsteady vortex lattice method, which is capable of simulating arbitrary subsonic maneuvers of the wing and accounts for the history of the motion, is employed to model the aerodynamics and feedback control via a distributed actuator is used for flutter and gust-load alleviation. The aerodynamic and structural grids do not have to be coincident. A controller that responds to induced loads and bending moments on the wing via a distributed actuator (e.g., piezoelectrics) by simultaneously decreasing the angle of attack is proposed.!23