UNSTEADY AERODYNAMICS OF ROLLING THICK DELTA WING WITH HIGH ASPECT RATIO

The objective of the present study is to experimentally examine rolling aerodynamics of a thick and relatively high aspect ratio delta wing. First, static aerodynamic forces of lift, drag, and pitching and rolling moments were measured with a sting balance with six force components. At an attack angle where lift becomes maximum, the wing was found to be unstable with regard to roll motion. Under post-stall conditions, highly non-linear characteristics were observed, and at some angles of attack, there exist several equilibrium points with regard to roll angle except for = 0°. Then, rolling transitional processes were examined by free-to-roll tests using a potentiometer to see the effects of unsteady aerodynamics. As a result, unsteady phenomena like wing rock were observed around several equilibrium points except for = 0°. Though these phenomena are self-induced oscillations, their mechanism seems to be different from wing rock oscillation. Nomenclature b wing span cr root chord