233 交番噴流の状態を支配するパラメータ(G05-3 剥離制御・抵抗低減,G05 流体工学)  [in Japanese] 233 Formation Parameters of Zero-Net-Mass-Flux Jet Flow Patterns  [in Japanese]

Flow fields of zero-net-mass-flux (synthetic) jets are categorized by four patterns named as 'a laminar jet', 'laminar rings', 'a transient jet', and 'a turbulent jet'. These flow patterns change the characteristics of the jets. It seemed that Reynolds number and Strouhal number are inadequate to determine the flow patterns of this type of jets. Then, we carried out additional experiments in another condition, and examine formation parameters and those combinations governed this flow fields. As a result, it turns out that these flow patterns are arranged with the non-dimensional parameter of Reynolds number and Womersley number multiplied by the square root of the contraction ratio of the area of a piston to that of an orifice.