Characterization of the suction and oscillatory blowing actuator in still air

The current study focuses on dynamic characterization of the Suction and Oscillatory Blowing (SaOB) actuator in still fluid as a pre-requisite to closed-loop flow control application. This stage should shed light on operational aspects, such as, the unsteady actuation characteristics, and the structure of the external, highly unsteady and complex flow. These aspects are studied through a series of experiments with a variety of experimental methods including unsteady pressures measurements, hot-wire anemometry, phase-locked and time resolved particle image velocimetry (PLPIV and TRPIV, respectively). Here we compare two TRPIV data reduction methods. We use proper orthogonal decomposition (POD) to filter the data (through small number of most energetic modes) and identify the most energetic coherent structures in the flow field. The current results should enable development of simplified boundary conditions for CFD. The suction effect, as well as the interaction of the actuation with a cross-flow boundary layer are under current study.