Switching mechanism of a jet in a wall-attachment device. (Switching of a jet by small rise-time control flow)

The switching process in a wall-attachment fluidic device has been assumed to be a quasi-steady flow, because the transport time of fluid particles from the nozzle to the splitter is short compared to the switching time. The assumption depends on the condition that the time constant of the control flow is approximately equivalent to the switching time. The switching mechanism of a jet by the control flow with a small rise time is analyzed by flow visualization and measurement of the switching time in an enlarged model. The switching time decreased with increasing control pressure though it has an asymptotic value. However, the switching time normalized by the virtual time constant of the control flow increasing control pressure. Also, a large control pressure reduced the effect of the opposite wall set-back on the switching of the jet.