"ROLL CONTROL USING A STAGNATION POINT ACTUATOR"

Darden, L.A. , Peterson, K., and Komerath, N.M.

AIAA 96-2498, Applied Aerodynamics Conference, June 1996

ABSTRACT
This paper presents linear transfer functions relating the movement of a nosetip stagnation point actuator to the roll moment induced on a wing-body at high angle of attack. Previous work using this actuator has shown contnuous, rapid control of forebody vortex asymmetry and established the linear cause-effect relationship between stagnation point displacement and vortex asymmetry. Roll moment coefficients were measured on a roll-constrained model at several roll angles. Excitation and elimination of wing rock was demonstrated. Here the roll moment data are related to the nose motion through linear transfer functions, and compact representations of the transfer functions are provided as a first step in developing controllers using the stagnation point actuator. The transfer function between nose motion and the surface pressure differential across the forebody is also presented, so that the pressure asymmetry can be related to the wing rolling moment. Finally, measurements of model roll inertia are presented.