The Application of Variable Cant Angle Winglets for Morphing Aircraft Control

This paper investigates a novel method of control for ‘morphing’ aircraft. The concept consists of a pair of winglets with adaptive cant angle, independently actuated, mounted at the tips of a flying wing. Computations with a vortex lattice model and wind tunnel tests demonstrate the validity of the concept. The variable cant angle winglet appears to be a multi-axis effector with a favorable coupling in pitch and roll with regard to turning manoeuvres. Nomenclature � angle of attack �e elevator deflection angle � reduced spanwise coordinate vortex strength l, r left and right winglet cant angles x vortex strength sensitivity w.r.t. variable x turn rate � bank angle � air density b wing span CD, CY , CL drag, side-force and lift coefficients Cl, Cm, Cn rolling, pitching and yawing moment coefficients CDx , CYx , CLx drag, side-force and lift coefficient derivatives w.r.t. parameter x Clx , Cmx , Cnx rolling, pitching and yawing moment coefficient derivativesw.r.t. parameter x croot root chord g gravitational acceleration p, q, r aircraft rotation rates in body or stability axes R turn radius u, v, w aircraft velocity components in body or stabilty axes Vcg flight speed W aircraft weight CG center of gravity LE leading edge TE trailing edge