Three-Jet Fluidic Oscillator Nozzle for Viscous Fluid Sprays
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Solution Overview
Problem
Existing fluidic oscillators struggle to reliably initiate and maintain oscillating sprays with cold or viscous fluids, particularly in automotive windshield washer applications, as their performance deteriorates with increasing fluid viscosity.
Innovation Solution
A nozzle assembly with a fluidic oscillator circuit featuring a novel geometry that includes a three-jet island configuration with specific jet intersection angles and island protuberances, which generates internal vortices to create a bistable periodic oscillation cycle, ensuring reliable initiation and maintenance of oscillating sprays across a wide range of temperatures and viscosities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fluidic oscillators are used, then they provide wear-free operation and reliable spray generation, but their performance deteriorates with increasing fluid viscosity and temperature
Solution Approach 1:
The patent modifies the geometric parameters of the fluidic oscillator, specifically the interaction chamber dimensions, jet angles, and island protuberance shape, to optimize performance with high-viscosity fluids. The interaction chamber width is set to 12.5-13.5 times the power nozzle width, and the axial length is 7.5-8.5 times the power nozzle width, creating parameters that maintain oscillation reliability across varying fluid conditions
Solution Approach 2:
The fluid circuit is divided into distinct functional sections: a power nozzle section with three separate nozzles for jet generation, an interaction chamber section for vortex formation, and an outlet section for spray emission. This segmentation allows each section to be optimized independently for its specific function while maintaining overall system reliability
2Temperature
If the fluid viscosity increases due to lower temperatures, then the fluid becomes harder to spray, but conventional oscillators fail to maintain sufficient oscillatory jet behavior
Solution Approach 1:
The patent introduces an asymmetric island protuberance within the interaction chamber that creates asymmetric flow paths for the three jets. This asymmetry generates stronger vortex formation and bistable periodic oscillation, which maintains reliable oscillatory behavior even with cold, high-viscosity fluids that would otherwise dampen oscillations in conventional symmetric designs
3Stability of the object's composition
If the jet intersection angle is optimized for uniform spray distribution, then the spray pattern improves, but the device complexity increases
Solution Approach 1:
The three-jet island configuration serves multiple functions simultaneously: it generates three coherent jets, creates vortex pairs through asymmetric interaction with the island, establishes bistable periodic oscillation, and produces uniform spray distribution. This multi-functionality achieves uniform spray composition without requiring additional complex components or adjustment mechanisms
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a durable, cost-effective, and reliable method for generating oscillating sprays with cold or viscous fluids, achieving higher spray velocities, improved fan angle range, and uniform distribution, enhancing performance in automotive and other applications.
Implementation Method 1
The first, second and third jets cause vortices to form and move about within the interaction chamber in a bistable periodic oscillation cycle
Implementation Method 2
first, second and third power nozzles, each having a floor and sidewalls that are configured to accelerate the movement of said pressurized fluid that flows through said first, second and third power nozzles to form a jet of fluid
Implementation Method 3
An oscillating liquid jet can yield a variety of spray patterns for the downstream distribution of the liquid droplets that are formed as this liquid jet breaks apart in the surrounding gaseous environment
Data Source
Figure 1A~1C
Figure 1D
Figure 1E
AI summary
A nozzle assembly includes a fluidic oscillator 100 operating on a pressurized fluid to generate an oscillating spray of fluid droplets, and the oscillator aims fluid jets from first, second and third power nozzles 114A, 114B, 114C into an interaction chamber 118 and toward an upwardly projecting island protuberance 126 defining first, second and third island wall segments. The outermost jets 114A, 114B are aimed at an obtuse angle of 100 to 140 degrees along axes which intersect beyond the island at a Jet intersection point, J|. The upstream end of interaction chamber 118 is defined by first and second laterally offset concave wall surfaces 142, 152 which define left side and right side vortex generating areas so that fluid jet steering vortices may be alternately formed and then displaced distally and shed to steer the fluid jet laterally within interaction chamber 118.