Cross-Flow Fan Guide Geometry for Lower Air Conditioner Wind Noise
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Solution Overview
Problem
Existing air conditioners with cross flow fans suffer from wind noise due to vortex airflow interference, which is not optimally addressed by prior solutions that compromise air-blowing performance.
Innovation Solution
The implementation of twisted portions on the rear guider and stabilizer, which are gradually deviated from the axial direction in the circumferential direction, creating a uniform shape across cross sections and reducing wind noise while maintaining air-blowing performance by ensuring continuous noise generation and airflow stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a rib with irregular shape is provided at the leading end portion of the front tongue portion to suppress wind noise, then wind noise is suppressed, but air-blowing performance is deteriorated
Solution Approach 1:
The patent applies curvature by deviating the twisted portions gradually from the axial direction in the circumferential direction, creating a twisted shape that is smooth and curved rather than irregular. This curved geometry suppresses wind noise by dispersing vortex airflow while maintaining uniform cross-sectional shapes that preserve air-blowing performance
Solution Approach 2:
The patent changes the geometric parameters of the tongue portions by introducing gradual deviation angles in the circumferential direction. The twisted portions have specific deviation angles that optimize both noise suppression and airflow characteristics, transforming the original straight axial geometry into a optimized twisted geometry
2Object-affected harmful factors
If twisted portions are provided to suppress wind noise, then wind noise is suppressed, but device complexity increases
Solution Approach 1:
The patent segments the tongue portions into multiple twisted portions, each with gradual deviation from the axial direction. This segmentation allows the complex noise suppression function to be achieved through multiple simple twisted sections rather than one complex irregular shape, making the design more manageable and manufacturable
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
This solution effectively suppresses wind noise by ensuring continuous noise generation without compromising air-blowing performance, as the twisted portions are designed to maintain airflow consistency and reduce interference between vanes and vortex airflow.
Implementation Method 1
Between each tongue portion and the fan, a vortex airflow is generated. When a vane of the fan passes this vortex airflow, wind noise (NZ noise) is generated on account of the interference between the vortex airflow and the vane.
Data Source
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AI summary
Wind noise is suppressed while an air-blowing performance is maintained. An indoor unit 1 of an air conditioner includes a cross flow fan 10 and a rear guider 20 and a stabilizer 32 which are provided on the respective sides of the outer periphery of the cross flow fan 10 to form an air passage. Each of the rear guider 20 and the stabilizer 32 has, at least at a part in the axial direction which part is on the leading end side, twisted portions 23, 37. In the circumferential direction of the cross flow fan 10, each twisted portion 23, 37 is deviated from the axial direction of the cross flow fan 10 gradually from one end to the other end.