A. Scotti

Active Aeroelastic Control over a Multisurface Wing: Modeling and Wind-Tunnel Testing

This paper presents the work that has been performed on a wind-tunnel aeroelastic wing model to implement a multisurface modal control system. Wing model realization, the control system, and experimental setup were described briefly here, together with a methodology used to numerically tune the simple control system. Usage of a multiple wind-tunnel test session has been adopted first to perform numerical-experimental correlations and then to optimize control parameters. The entire control system demonstrates the capability to damp the wing bending and torsion modes while still remaining stable within the flight envelope.

Design, Manufacturing and Preliminary Test Results of an Adaptive Wing Camber Model

In the present paper, a new device developed to implement the Active Adaptive Wing Camber (AAWC) concept is analyzed in details and the results of the preliminary experimental results are reported. The AAWC concept is related to a more general concept of Mission Adaptive Wing, i.e. a wing able to adapt itself, by means of configuration and/or shape variation, to changes of flight conditions during the mission, so as to maximize some performance indices. The proposed device is based on a modification of the original idea proposed by Dr. Monner from DLR and called for sake of simplicity Rotating Ribs (RR) concept. To test the reliability of the proposed concept, a wing model has been designed and manufactured. The results of the preliminary static tests and the correlations to numerical predictions are reported in the following.

Active Control of Three-Surface Aeroelastic Model

The present paper describes research activities related to the Active Aeroelastic Aircraft Structures Project, fulfilled by Politecnico di Milano, dealing with the aeroelastic demonstrator named X-DIA. This aircraft is a one-tenth geometrically and dynamically scaled model of a regional transport airplane, and it has been built to become a wind-tunnel benchmark for experimenting with new aeroelastic concepts. All movable foreplane surfaces and wings with distributed multiple control surfaces are here installed to improve overall aeroelastic response and thus to improve airplane stability and even fuselage flight comfort. An identical location of accelerations and forces-based control system has been implemented: numerical and experimental results show a remarkable capability of this device in damping fuselage bending and torsion modes. The following pages will provide information about the research project, describing methodologies adopted and experiment results taken in wind-tunnel testing.

Wind Tunnel Testing of an Active Controlled Wing Under Gust Excitation

This paper summarizes the activity performed on the aeroelastic demonstrator X-DIA at Politecnico di Milano, dealing with active aeroelastic control. A control system based on aerodynamic energy concept has been implemented and installed on a forward swept wing. Tuning of control system parameters were obtained through a genetic algorithm procedure. Validation of the control system was performed with wind tunnel testing using specific device, i.e. a gust generator, specifically built for the purpose. Details about the gust vane device, about its tuning and about wing testing will be provided in the following pages. Wing control system shows capability of increasing damping for wing bending mode when the wing is excited by either discrete and stochastic gust.

Aeroelastic Testing on a Three Surface Airplane

This article presents the work developed on a three surface aeroelastic demonstrator during the research project named 3AS. Active control of two independent canard wings has been used to damp fuselage modes with the direct aim of improving aeroelastic response of the airplane under analysis. Hardware used, free-free suspension system, and wind tunnel testing results will be presented, together with model status development, giving a preliminary view of future works and on-going activities involving the model.

Experimental Investigations of a Vibration Suppression System for a Three-surface Aeroelastic Model

This article deals with the experimental activity that has been taken during the period May-June 2004 at VZLU wind tunnel facility by Politecnico di Milano and VZLU, as partners of Active Aeroelastic Aircraft Structures (3AS) EU project. An airplane fuselage where an all movable fore-plane was installed has been tested dynamically, to check out effectiveness of an active control system based on ILAF concept. The following pages will show how the model has been realized, its features and behavior. Results will show that significant fuselage damping can be achieved with two different canard configurations.

Nonlinear X-DIA Wing Response to the Oscillations of a Control Surface

The ability to model nonlinear wing/control surface relations is an essential component for the design and implementation of nonlinear control laws that make use of control surfaces and exploit these relations. In this work, an experimental investigation is conducted to determine nonlinear wing response to the oscillations of a control surface of an aeroelastic demonstrator. Higher-order spectral moments are applied to identify quadratic and cubic nonlinearities. The results show enhanced response of the wing at the excitation frequency. Additionally, the wing’s response is characterized by quadratic and cubic nonlinearities.