Affiliations: School of Aeronautics and Astronautics, Purdue
University, 315 North Grant Street, West Lafayette, Indiana 47907, USA. E-mail:
[email protected] | School of Aeronautics and Astronautics, Purdue
University, 315 North Grant Street, West Lafayette, Indiana 47907, USA | Advanced Fluidics Corporation, 4217 Red Bandana Way,
Ellicott City, Maryland 21042, USA
Abstract: The fluidic oscillator is a device that generates an oscillating jet
when supplied with fluid at pressure. The oscillator has no moving parts –
the creation of the unsteady jet is based solely on fluid-dynamic interactions.
Fluidic oscillators can operate at frequencies ranging up to 20 kHz, and are
useful for flow control applications. The fluidic oscillator evaluated in the
current study is comprised of two fluid jets that interact in an internal
mixing chamber, producing the oscillating jet at the exit. Both porous
pressure-sensitive paint (PSP) and dye-colored water flow are used to visualize
the internal and external fluid dynamics of the oscillator. Porous PSP
formulations have been shown to have frequency responses on the order of 100
kHz, which is more than adequate for visualizing the fluidic oscillations. In
order to provide high-contrast PSP data in these tests, one of the internal
jets of the fluidic oscillator is supplied with oxygen, and the other with
nitrogen. Results indicate that two counter-rotating vortices within the mixing
chamber drive the oscillations. It is also shown that the fluidic oscillator
possesses excellent mixing characteristics.
Keywords: Fluidic oscillator, Pressure-sensitive paint, Fluid mixing, Flow control
