Open loop transient forcing of an axisymmetric bluff body wake

Siegel S., Seidel J., Cohen K., Aradağ Çelebioğl S., Mclaughlin T.

46th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, United States Of America, 7 - 10 January 2008 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Reno, NV
  • Country: United States Of America
  • TED University Affiliated: No


Unforced and open loop forced experiments of the axisymmetric wake at ReD=1,500 are analyzed to explore the effect of forcing. Particle Image Velocimetry (PIV) is used to acquire flow data in slices of the wake with the goal of establishing observability of the flow structures. In the unforced wake, because of the axial symmetry, structures do not maintain a constant azimuthal phase over time. Forcing with a fixed phase is therefore introduced to study the wake structures in detail. The results of a parameter study of forcing frequency and amplitude are used to establish a "lock-in" region where the flow responds to forcing, similar to prior investigations of the wake behind a circular cylinder. We are able to experimentally verify the extent of frequencies and forcing amplitudes for which the flow locks into the forcing input. The data obtained from these experiments provide the baseline dynamic model in order to develop controllers for feedback controlled simulations and experiments of the axisymmetric bluff body wake.