Flow oscillating characteristics of fluidic oscillator pairs using the interbridge method

In this study, fluidic oscillator pairs were devised to include a connection of feedback ports with an interbridge and a removal of inner feedback loops. Each fluidic oscillator pair was designed by aiming synchronization of the sweeping jets. Numerical simulations of the four fluidic oscillator pairs were carried out to observe and evaluate both flow and sweeping characteristics of each fluidic oscillator pair under a nozzle pressure ratio of 3.0. The numerical setup was validated through a comparison between the experimental results and computational simulation results. The results indicate that, based on the interbridge arrangements, the main flows in two fluidic oscillators were synchronized by flow interaction via interbridges. Consistent in-phase jets and out-of-phase jets were obtained. By arranging an inport bridge and an outport bridge between each fluidic oscillator and removing the inner feedback loops, in-phase jets were obtained. By contrast, by arranging an outport bridge between each fluidic oscillator, out-of-phase jets were obtained. Meanwhile, when a chamber bridge was additionally arranged between the recirculation chambers of each fluidic oscillator, increases in the sweeping frequency and flow instability were observed. In addition, the relationship between the recirculation in the recirculation chamber and the sweeping characteristics was quantitatively evaluated.