Temporal Analysis of Jet and Vortex Actuator (java) – Induced Flows
An oscillatory, zero-net-mass flux Jet and Vortex actuator (JaVA) was built and tested in a still water tank. The striking feature of this JaVA model is that it can produce different flow types ranging from vertical through oblique to wall-parallel jets or vortices mainly depending on the chosen actuation frequency and amplitude. These flow types have been investigated using flow visualizations and by extracting quantitative velocity data using a gradient-based optical flow concept. The temporal behavior of basic JaVA-induced flow types have been further investigated using Fourier analysis. All quantitative features mentioned in Ref. 3 have been reproduced but our results are much more detailed and consist of instantaneous velocity fields for quantitative analysis. In addition, we have found that the actuator plate’s mean position is another important parameter which significantly affects the JaVA-induced flow types.