Unsteady Aerodynamic Forces on an Oscillating Wing at High Incidences and Flow Separation.

Abstract

Based on wind tunnel measurements on a low-aspect-ratio trapezoidal half-wing model in incompressible flow, some characteristic features of motion-induced unsteady airloads at high incidences and flow separation are presented and discussed. Special emphasis is placed on the effect of the motion of the wing on the flow separation processes and on the investigation of the interactions between the separated flow phenomena on the stationary wing and the motion-induced unsteady airloads on the oscillating wing. It is shown that these airloads are strongly affected by the flow separations and that their prediction from inviscid potential-flow theory may lead to rather unrealistic results in buffeting response calculations.