SUMMARY

The proposed doctoral research builds on previous work which demonstrated that enhancement or suppression of inherent flow coupling to a static axisymmetric body has significant effects on the evolution of its near wake, and consequently on its global unsteady aerodynamic loads (forces and moments). The proposed investigation will extend these findings to the unsteady mechanisms of aerodynamic flow control on the dynamics of a moving bluff body, with an emphasis on the reciprocal couping between the wake instabilities and body motion. 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 by fluidic actuation. The underlying hypothesis of the proposed research is that active alteration of the wake of a moving body will enable prescribed modification of the time-dependent aerodynamic loads, and, consequently, enable active control of its trajectory and stability. In the proposed work, a wire-mounted axisymmetric bluff body integrated with individually-controlled miniature fluidic actuators will undergo prescribed motions using a unique, programmable 6-DOF traverse. The interactions between the actuation and the cross flow with their coupling to the stability of the near wake will be investigated using particle image velocimetry (PIV), hot-wire anemometry, and a real time 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. It is anticipated that understanding of the coupled stability mechanisms of a moving body in the limit of a free flight can help pave the way towards transition of these active flow control technologies to a number of practical applications.