SUMMARY

The unsteady flow mechanisms of aerodynamic flow control of the reciprocal coupling between a bluff body and its wake flow are investigated using fluidic actuation at the moving flow boundary. The proposed investigations build on our preliminary findings that demonstrated that enhancement or suppression of this inherent flow coupling can have a profound effect on the evolution of its near wake, and consequently on the global unsteady aerodynamic loads. Of particular interest is the evolution and control of side forces that are associated with asymmetries of forebody counter-rotating vortices. It is anticipated that controlled manipulation of these fundamental coupling mechanisms will lead to the realization of new aerodynamic states that are unattainable on static platforms, and thus broaden the range and bandwidth of the induced aerodynamic loads. The underlying hypothesis of the proposed research is that alteration of the characteristic of the body’s near wake will enable prescribed modification of its time-dependent aerodynamic loads, and, consequently, enable active control of its motion and stability. The proposed wind tunnel investigations are conducted using a wire-mounted axisymmetric bluff body integrated with individually-controlled miniature fluidic actuators will undergo prescribed canonical motions using a programmable 6-DOF traverse. The interactions between the actuation and the cross flow and their coupling to the stability of the near wake is investigated using high-speed PIV and a motion analysis system. The velocity and force data will be used to link the evolution of the wake and the motion of the body to the aerodynamic loads.