Wake flow stabilization with DBD plasma actuators for low Re numbers

J D'ADAMO; R SOSA; M BARCELO; G ARTANA

Colonia Sacramento

Congreso; Fluidos 2010 XI Reunión sobre Recientes Avances en Física de Fluídos y sus Aplicaciones; 2010

División Fluidos-AFA

We propose to study the stability properties of a wake air flow forced by electrohydrodynamic (EHD) actuators. EHD actuators can add momentum to the flow around an object in regions close to the wall. Hence, we adopt the hypothesis of the forcing actuation modeled as a slip-wall condition. We study the flow around a cylinder modified by EHD actuators, dielectric barrier discharge (DBD) type, by means of particle image velocimetry (PIV) measures. For the sake of simplicity we observed flows at low Reynolds(Re) numbers (~ 200) where the flow is mainly two-dimensional. As the forcing frequencies, characteristic of DBD, are much higher than the natural shedding frequency of the flow (kHz vs. Hz), we consider in this work only the forcing actuation as stationary. The actuators are disposed symmetrically near the boundary layer separation point. Thus, flow symmetry is conserved, as it remains weakly non parallel. This aspect allows us to perform stability analysis of the flow and to determine its characteristics which are governed by a strong mean flow correction. We also present results on the global mode evolution under forcing. The main motivation of this work is to optimize the forcing on the flow, leading to a more effective energy consumption of EHD actuators.