Fluidic Oscillating Nozzle for Sweeping Air Flow
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Solution Overview
Problem
Existing systems for generating oscillating air flows, such as those used in lawn sweeping and leaf blowing, are complex, expensive, and inefficient, leading to operator fatigue and incomplete cleaning due to the need to move the entire air source for sweeping motions.
Innovation Solution
A fluidic device with a converging nozzle assembly and inertance loop that produces a high-velocity, oscillating air flow with minimal pressure drop, allowing for a variable and periodic flow that can be directed without moving the entire air source, using a three-segment nozzle structure with a power nozzle, control ports, and a setback region to control the frequency of oscillation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional pumps or fans with control circuits are used to generate periodic pressurized pulses, then the desired oscillating air flow is achieved, but the system becomes complex and expensive to manufacture and maintain
Solution Approach 1:
The patent replaces mechanical control systems (pumps with control circuits, switching valves) with a purely fluidic oscillating nozzle system. The oscillation is generated by fluid dynamic principles within the nozzle geometry itself, eliminating the need for external mechanical actuators, control circuits, and switching valves, thereby reducing device complexity while maintaining cleaning effectiveness
Solution Approach 2:
The fluidic oscillating nozzle is self-regulating and self-oscillating based on the air flow rate passing through it. The system automatically adjusts its oscillation characteristics according to the incoming air flow without requiring external control mechanisms, making the system simpler and more reliable
2Ease of operation
If the entire air source is moved to produce a sweeping motion for cleaning surfaces, then complete area coverage is achieved, but operator fatigue increases and efficiency decreases
Solution Approach 1:
The patent introduces dynamic oscillation to the air flow pattern by using a fluidic oscillating nozzle that automatically produces sweeping side-to-side motion. This dynamic flow pattern allows the air jet to cover a wider area without requiring the operator to physically move the entire air source, reducing operator fatigue while maintaining comprehensive cleaning coverage
Solution Approach 2:
The nozzle produces periodic oscillating air flows that sweep back and forth across the cleaning surface. This periodic action creates an effective sweeping motion that covers a broader area over time, achieving the same cleaning coverage as manual sweeping motions but with less physical effort from the operator
3Productivity
If a fluidic oscillator with abrupt changes in cross-sectional area is used, then the oscillating flow is generated, but the flow uniformity and symmetry deteriorate
Solution Approach 1:
The patent employs smooth curved transitions and sinusoidal profiles throughout the nozzle geometry, avoiding abrupt changes in cross-sectional area. The smooth curvature of the fluid passages maintains flow uniformity and symmetry while still generating the desired oscillating flow pattern, preventing flow separation and turbulence that would result from sharp transitions
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 device reduces operator fatigue and improves cleaning efficiency by allowing for a wider sweeping motion with minimal hand effort, effectively clearing debris without the need to move the air source, while maintaining a high flow rate and adjustable frequency.
Implementation Method 1
A converging nozzle assembly defining a tapered internal lumen having a smooth sinusoidal profile is configured to generate at a power nozzle a high velocity stream with minimal pressure drop
Implementation Method 2
an inertance loop of selected cross sectional area and length interconnecting and providing fluid communication between the first control port and the second control port
Data Source
Figure 1~2
Figure 3~6
Figure 4~4A
AI summary
An oscillating or pulsing fluid stream, or flow (18, 132, 300), is produced from a flow of pressurized air by fluidic apparatus (10, 100, 130, 180, 220) in a device (250) configured for use in surface cleaning, sweeping, lawn car applications, and the like. Converging inlet chamber walls (20, 22) define a tapered internal lumen having a smooth narrowing profile is configured to generate at a power nozzle (44) a high velocity steam with minimal pressure drop. Downstream of the power nozzle, first and second control ports (CP1, CP2) are in fluid communication with the high velocity steam (46) and with each other via an inertance loop (72) having a lumen of selected cross sectional area and length. The varying air flow is directed through an outlet chamber (14, 134) shaped to produce an oscillating flow (18) or a pulsating flow (132).