Investigation of the experimental active control of a typical section airfoil using a trailing edge flap

Abstract

This paper presents an experimental implementation of an active control system used to suppress °utter in a typical section airfoil.The H 2 optimal control system design is based upon experimental system identi¯cations of the transfer functions between three measured system variables: pitch, plunge, and °ap position and a single control signal which commands the °ap of the airfoil.Closed-loop response of the airfoil demonstrated gust-alleviation below the openloop °utter-boundary.In addition, the °utter boundary was extended by 12.4% through the application of active control.Cursory robustness tests demonstrate stable control for variations in °ow-speed of §10%.