Gust Loads Alleviation Using Special Control Surfaces

Abstract

Control laws are designed for the alleviation of dynamic gust loads on a wind-tunnel model of a transport aircraft using wing-mounted control surfaces. Three different control surfaces are used: the symmetrically actuated main ailerons, special underwing forward-positioned control surfaces at about 0.8 of the wingspan, and special wing-tip forward-positioned control surfaces. The 5.3-m-span cable-mounted wind-tunnel model was constructed at the TsAGI laboratories and is being tested as there part of the 3AS 5th Framework European Commission research project. The length of one-minus-cosine vertical gust velocity profile is tuned to yield maximal wing-root bending moment All the control laws are based on simple low-pass filters for easy and robust application in the wind tunnel. Each is based on single input of a wing-tip accelerometer, which is shown to react sufficiently before the peak of the wing-root bending moment