Cold-performance fluidic oscillator
View Patent ↗A fluidic oscillator suitable for use at colder temperatures for generating an exhaust flow in the form of an oscillating spray of fluid droplets has an inlet for pressurized fluid, a pair of power nozzles configured to accelerate the movement of the pressurized fluid, a fluid pathway that connects and allows for the flow of pressurized fluid between its inlet and the power nozzles, an interaction chamber which is attached to the nozzles and receives the flow from the nozzles, a fluid outlet from which the spray exhausts from the interaction chamber, and, at each power nozzle, a step in the height elevation of the floor of the power nozzle with respect to that of the interaction chamber for increasing the instability of the flow from the power nozzles.
1. A fluidic oscillator that operates on a pressurized fluid flowing through said oscillator to generate an exhaust flow in the form of an oscillating spray of fluid droplets, said oscillator comprising:
an inlet for said pressurized fluid,
at least a pair of power nozzles, each of which having a floor and sidewalls that are configured to accelerate the movement of said pressurized fluid that flows through said nozzles so as to form a jet of fluid that flows from each said power nozzle,
a pathway that connects and allows for the flow of said fluid between said inlet and said power nozzles, said pathway having a boundary surface that includes a pair of sidewalls,
an interaction chamber attached to said nozzles and which receives said jet flows from said nozzles, said interaction chamber having a floor,
an outlet from which said spray exhausts from said interaction chamber, and
a step in the height elevation of the floor of said power nozzles with respect to that of said interaction chamber.
2. The fluidic oscillator as recited in claim 1 , wherein:
said steps having a specified height and said power nozzles having a specified height, and
the ratio of said step height to said power nozzle height is in the range of 0.10 to 0.20.
3. The fluidic oscillator as recited in claim 2 , wherein said power nozzles being situated with respect to said interaction chamber such that the centerlines from the exits of said power nozzles intersect at an angle in the range of 160 to 190 degrees.
4. The fluidic oscillator as recited in claim 2 , wherein said power nozzles being situated with respect to said interaction chamber such that the centerlines from the exits of said power nozzles intersect at an angle of approximately 175 degrees.
5. A method of forming an oscillating spray of fluid droplets, said method comprising the steps of:
causing a pressurized fluid to flow into an inlet,
placing at least a pair of power nozzles downstream from said inlet and configuring each of said nozzles with a floor and sidewalls so as to accelerate the movement of said pressurized fluid when said fluid flows through said nozzles so as to form a jet of fluid that flows from each said power nozzle,
using a fluid pathway to connect and allow for the flow of said fluid between said fluid inlet and said power nozzles, said pathway having a boundary surface that includes a pair of sidewalls,
attaching an interaction chamber downstream from said nozzles and configuring said chamber with a floor and so as to receive said jet flows from said nozzles,
providing said chamber with a fluid outlet from which said spray exhausts from said interaction chamber, and
utilizing a step in the height elevation of the floor of said power nozzles with respect to that of said interaction chamber.
6. The method as recited in claim 5 , wherein:
said steps having a specified height and said power nozzles having a specified height, and
the ratio of said step height to said power nozzle height is in the range of 0.10 to 0.20.
7. The method as recited in claim 6 , wherein said power nozzles being situated with respect to said interaction chamber such that the centerlines from the exits of said power nozzles intersect at an angle in the range of 160 to 190 degrees.
8. The method as recited in claim 6 , wherein said power nozzles being situated with respect to said interaction chamber such that the centerlines from the exits of said power nozzles intersect at an angle of approximately 175 degrees.
9. A fluid spray apparatus comprising:
a fluidic insert that operates on pressurized fluid flowing through said insert to generate an exhaust flow in the form of an oscillating spray of fluid droplets, said insert having a fluidic circuit molded into said insert,
said fluidic circuit having:
an inlet for said pressurized fluid,
at least a pair of power nozzles, each of which having a floor and sidewalls that are configured to accelerate the movement of said pressurized fluid that flow through said nozzles so as to form a jet of fluid that flows from each said power nozzle,
a pathway that connects and allows for the flow of said fluid between said inlet and said power nozzles, said pathway having a boundary surface that includes a pair of sidewalls,
an interaction chamber attached to said nozzles and which receives said jet flows from said nozzles, said interaction chamber having a floor,
an outlet from which said spray exhausts from said interaction chamber, and
a step in the height elevation of the floor of said power nozzles with respect to that of said interaction chamber.
10. The fluid spray apparatus as recited in claim 9 , wherein:
said steps having a specified height and said power nozzles having a specified height, and
the ratio of said step height to said power nozzle height is in the range of 0.10 to 0.20.
11. The fluid spray apparatus as recited in claim 10 , wherein said power nozzles being situated with respect to said interaction chamber such that the centerlines from the exits of said power nozzles intersect at an angle in the range of 160 to 190 degrees.
12. The fluid spray apparatus as recited in claim 10 , wherein said power nozzles being situated with respect to said interaction chamber such that the centerlines from the exits of said power nozzles intersect at an angle of approximately 175 degrees.