Aerospace Control and Guidance Systems Committee

Announcements

You must first log in to access prior meeting presentations, register for a meeting, or nominate some for the Ward Award.

If you do not have a login account, or cannot remember the email address associated with your account, please click on the Application Form link below.

Login

Site Search

Search our site:

Upcoming Events

Photos

Meeting Highlights New!

Subcommittee S

Prior Meetings

Abstracts may be viewed by anyone. Presentations are only available to active members who have logged in.

Meeting 132
(coming soon)

Home

Ward Memorial Award

Planning Advisory Board

Downloads

Constitution and By-Laws

About

History

Contact Us

← Return to agenda

Meeting	ACGS Committee Meeting 119 - Fairborn, OH - March 2017
Agenda Location	6 SUBCOMMITTEE A – AERONAUTIC AND SURFACE VEHICLES 6.3 Aeroservoelastic Modeling of Body Freedom Flutter for Control System Design
Title	Aeroservoelastic Modeling of Body Freedom Flutter for Control System Design
Presenter	Jeffrey Ouellette
Affiliation	NASA Armstrong
Available Downloads*	presentation
	Downloads are available to members who are logged in and either Active* or attended this meeting.
Abstract	One of the most severe forms of coupling between aeroelasticity and flight dynamics is an instability called body freedom flutter. The existing tools often assume relatively weak coupling, and are therefore unable to accurately model body freedom flutter. Because the existing tools were developed from traditional flutter analysis models, inconsistencies in the final models are not compatible with control system design tools. To resolve these issues, a number of small, but significant changes have been made to the existing approaches. A frequency domain transformation is used with the unsteady aerodynamics to ensure a more physically consistent stability axis rational function approximation of the unsteady aerodynamic model. The aerodynamic model is augmented with additional terms to account for limitations of the baseline unsteady aerodynamic model and to account for the gravity forces. An assumed modes method is used for the structural model to ensure a consistent definition of the aircraft states across the flight envelope. The X-56A stiff wing flight-test data were used to validate the current modeling approach. The flight-test data does not show body-freedom flutter, but does show coupling between the flight dynamics and the aeroelastic dynamics and the effects of the fuel weight.