Fluidic Nozzle Oscillating Spray Mechanism

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Solution Overview

Problem

Existing fluidic nozzle assemblies lack adequate dynamic and cold performance for automotive, industrial, and consumer applications, particularly in windshield washing systems, where they fail to provide even fluid distribution and sufficient spray velocity with cold liquid mixtures.

Innovation Solution

A fluidic nozzle assembly with a cyclic jet wall attachment-detachment mechanism, featuring a power nozzle, vortex-generating cavities, and strategically designed interaction regions with adjustable dimensions to produce an oscillating spray with fan angles from 15° to 135°, enhancing dynamic and cold performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traditional fluidic circuits are used, then the nozzle structure is simple, but the spray velocity and dynamic performance are insufficient

Engineering Contradiction:
Improvespray velocityVSAvoidfluidic circuit complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The fluidic circuit is divided into multiple functional sections: a power nozzle section that generates the primary jet, a jet-steering section with cavities that directs and oscillates the jet, and an interaction region that amplifies the oscillation. This segmentation allows each section to be optimized for its specific function, achieving high spray velocity through the power nozzle while the steering section adds oscillation complexity only where needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circuit incorporates a dynamic jet-steering mechanism where the fluid jet rhythmically attaches to and detaches from opposite walls in the interaction region. This dynamic behavior is controlled by the geometry of the cavities and the position of inwardly projecting features, creating an oscillating spray pattern that enhances dynamic performance while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #15Dynamics

2Shape

If the fluid jet dwells at the extremes of travel, then the fan angle is increased, but the fluid distribution becomes heavy-ended

Engineering Contradiction:
Improvefan angleVSAvoidfluid distribution uniformity
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The circuit creates different flow conditions in different regions: the power nozzle section produces a high-velocity core jet, while the jet-steering cavities create regions of varying pressure and flow attachment. The interaction region geometry is specifically designed to control where the jet attaches along the walls, allowing the fan angle to be optimized independently from the fluid distribution pattern within the fan.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fluid jet undergoes periodic attachment and detachment from opposite walls in the interaction region, creating an oscillating spray pattern. This periodic action ensures that fluid is distributed throughout the entire fan angle range over time, preventing heavy-ended distribution while maintaining a large maximum fan angle through the oscillation mechanism.

Inventive Principle:
Principle #19Periodic action

3Speed

If the circuit is designed for high spray velocity, then dynamic performance is improved, but cold performance with viscous fluids deteriorates

Engineering Contradiction:
Improvespray velocityVSAvoidcold performance
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The circuit geometry parameters are specifically optimized to maintain performance across a range of fluid viscosities. The power nozzle dimensions, cavity sizes, and interaction region geometry are designed to ensure that the jet remains stable and oscillates correctly whether the fluid is cold and viscous or warm and less viscous, achieving both high spray velocity and reliable cold performance.

Inventive Principle:
Principle #35Parameter changes

4Shape

If a splitter is added to increase fan angle, then the maximum fan angle increases, but the spray pattern becomes center-heavy

Engineering Contradiction:
Improvefan angleVSAvoidspray pattern uniformity
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

Instead of using a splitter, the circuit segments the flow into a power nozzle section and a jet-steering section. The jet-steering cavities and interaction region work together to distribute fluid evenly across the fan angle through rhythmic wall attachment-detachment, achieving a large fan angle without the center-heavy distribution pattern that would result from using a splitter.

Inventive Principle:
Principle #1Segmentation

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 achieves improved dynamic and cold performance by generating a planar oscillating spray with larger, faster droplets, ensuring even fluid distribution and increased spray velocity, suitable for various applications including windshield washing.

Implementation Method 1

The fluidic oscillator of Fig. 2 includes a power nozzle 150, a jet-steering section 140, and an interaction region 160 and operates on a cyclic jet wall attachment-detachment mechanism resulting in an oscillating jet stream and subsequent spray.

Methodology Applied
Scientific EffectJet wall attachment-detachment mechanism:

Implementation Method 2

there is a bell-shaped feed leading to the power nozzle which produces a fluid jet with a turbulent boundary layer that is desirable to form vortices inside an interaction region

Methodology Applied
Scientific EffectVortex generation: Vortex Ring

Implementation Method 3

The fluidic oscillator or fluidic circuit operates on a fluid jet wall attachment-detachment cycle, with the jet at the center, large vortices are formed on either or opposing (A or B) sides and the jet attaches to either the A wall or the opposing B wall.

Methodology Applied
Scientific EffectCoanda effect: Coanda Effect

Data Source

PatentEP2931435B1Fluidic nozzle and oscillator circuit
Publication Date: 2020.07.22 DLHBOWLES INC
  • EP2931435B1 patent drawingFigure 1A~1C
  • EP2931435B1 patent drawingFigure 1D
  • EP2931435B1 patent drawingFigure 1E

AI summary

A fluidic circuit (200) configured to spray an oscillating pattern of fluid droplets, having an inlet (210) in fluid communication with a source and including a power nozzle (250) with an oscillation chamber having a fluid jet steering section (240) in fluid communication with the power nozzle and having a first fluid pressure accumulating volume opposite (242) a second fluid pressure accumulating volume (244). The fluid jet steering section (240) is in fluid communication with and emits a fluid jet into an oscillation inducing interaction region (260) with opposing first and second side wall features (262, 264) which define an oscillation inducing interaction region in the oscillation chamber for causing the jet of fluid (300) to rhythmically sweep back and forth between the sidewalls in the oscillation chamber.