Fluidic oscillator and spray-forming output chamber

DETAILED DESCRIPTION In accordance with the present invention a fluidic oscillator includes a chamber having a common inlet and outlet opening through which a fluid jet is issued across the chamber.
Upon impacting the far wall of the chamber the jet forms two oppositely rotating vortices, one on either side of the jet, which alternate in strength and position in opposite phases in the chamber.
Each vortex alternately conducts more or less fluid out of the common opening on its side of the jet.
The alternating outflows may be issued as fluid pulses for a specific utilization or may be used in conjunction with the output chamber described below to achieve a desired spray pattern.
Still another utilization of the oscillator is as a flow meter whereby the oscillator is disposed in a flow path and its oscillation frequency is measured to provide a linear function of flow.
This configuration has been found to be relatively insensitive to dimensional manufacturing tolerance variations, and operates over a wide range of fluid characteristics.
In accordance with another aspect of the present invention an output chamber for a fluidic oscillator receives fluid pulses in alternating opposed rotational directions.
An output vortex is established in the output chamber and is alternately spun in opposite directions by the alternating input pulses.
One or more outlet openings at the periphery of the output chamber issue a sweeping spray that is determined by the vectorial sum of two flow components: a first component is directed tangential to the output vortex and has a magnitude proportional to the instantaneous flow velocity at the output vortex periphery; a second component is directed generally radially outward from the output vortex and is a function of the static pressure at the vortex periphery and the net flow rate into the output chamber.
By reducing the static pressure in the chamber, for example by making the outlet opening wider or reducing the inflow, the frequency, droplet size and spray angle can be selected accordingly