Abstract
This study has been performed to clarify the behavior of the fluidic sonic oscillator. First we reconsider the propagation of pressure waves in the connecting tube during oscillation. Then we experimentally investigate the switching characteristics of wall reattachment fluidic devices and the mechanism of generation of pressure wave at the switching.
The results obtained can be summarized as follows:
1) In a sonic oscillator, the difference of pressure in two control ports just before the jet switching is at most zero. Therefore it is necessary that the switching pressure difference of the device for a sonic oscillator is less than or equal to zero.
2) When the mean pressure in two control ports is less than a certain value, the switching pressure difference of the device becomes less than or equal to zero. And the connection of the control ports by a tube can generate the sonic oscillation, if the mean pressure in the tube becomes lower than the value mentioned above.
