Cross Flow Fan Blade Protrusion Vortex Control
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Solution Overview
Problem
Conventional cross flow fans in air conditioners generate noise and vibration due to vortex formation, leading to reduced efficiency in air discharge and overall performance.
Innovation Solution
Incorporating a protrusion at the end of one or more blades of the cross flow fan, which extends downward and is connected to the outer edge in a curved surface, reduces vortex generation and enhances air discharge efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional blades are used in the cross flow fan, then the structure is simple, but vortexes are generated in the discharged air stream causing noise and vibration
Solution Approach 1:
The blade structure is modified by adding a protrusion at a specific location (one end of the blade) while keeping the rest of the blade structure unchanged. This localized modification creates a specific flow control function at the protrusion location to reduce vortexes, thereby reducing noise and vibration without significantly increasing overall device complexity.
Solution Approach 2:
The protrusion on the blade is designed to interact with the air flow in a way that converts the harmful vortex formation into beneficial flow control. The protrusion creates controlled turbulence that prevents large-scale vortex formation, thereby reducing noise and vibration while maintaining or improving air discharge efficiency.
2Productivity
If conventional blades are used in the cross flow fan, then manufacturing is simple, but air discharge efficiency deteriorates due to vortex formation
Solution Approach 1:
The protrusion is added only at one end of the blade rather than modifying the entire blade structure. This localized modification minimizes the impact on manufacturing complexity while effectively improving air discharge efficiency by controlling vortex formation at the critical discharge region.
Solution Approach 2:
The protrusion adds a third-dimensional feature to the blade structure, creating a more complex three-dimensional flow control surface. This dimensional addition allows the blade to better manage air flow in multiple directions, improving discharge efficiency while the protrusion's simple geometry keeps manufacturing relatively straightforward.
3Productivity
If blades rotate to discharge air, then air discharge function is achieved, but vortexes are generated causing performance deterioration
Solution Approach 1:
The rotating blade with protrusion converts the naturally occurring vortex formation into a controlled flow pattern. The protrusion creates small-scale turbulence that prevents large-scale vortex formation, thereby reducing harmful effects while maintaining the air discharge function. The rotation combined with the protrusion geometry creates a beneficial flow control effect.
Solution Approach 2:
The protrusion changes the geometric parameters of the blade, specifically adding a localized feature that alters the flow separation characteristics. This parameter change modifies the vortex formation process, reducing the intensity and size of vortices while maintaining effective air discharge during blade rotation.
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 effectively minimizes noise and increases air discharge efficiency, improving the performance of the cross flow fan by controlling vortex formation and optimizing airflow.
Implementation Method 1
such a cross flow fan according to the related art generates vortexes in the stream of air being discharged
Implementation Method 2
the outer surface of the protrusion facing outwardly of the cross flow fan may be smoothly connected to an outer edge surface of the blade
Data Source
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AI summary
A cross flow fan and an air conditioner including the cross flow fan, where the cross flow fan includes a fixing member (120), and a plurality of blades (110) fixed to an upper surface of the fixing member and spaced apart from each other in a circumferential direction. One or more of the blades (110) include a protrusion (113) protruding in a downward direction from a surface of the blade.