Centrifugal Fan Blade Leading Edge Interference Grooves for Noise Reduction
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Solution Overview
Problem
Centrifugal fan blade assemblies generate significant aerodynamic noise due to the impact of high-speed air flows on their thin and sharp leading edges, which affects daily activities.
Innovation Solution
The centrifugal fan blade assembly incorporates V-shaped interference grooves on the leading edges of the blades, with specific dimensions and distributions to alter noise frequencies and reduce broadband noise generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the leading edge of the blade is designed to be thin and sharp, then the aerodynamic performance is improved, but the broadband noise increases significantly
Solution Approach 1:
The patent applies local quality by introducing interference grooves only at specific locations (leading edge of the blade) rather than modifying the entire blade structure. The grooves create localized flow disturbances that suppress broadband noise while preserving the overall thin and sharp leading edge geometry needed for aerodynamic performance
Solution Approach 2:
The patent changes physical parameters by introducing interference grooves with specific geometric parameters (depth, width, spacing) on the leading edge. These parameter modifications alter the flow characteristics locally, transforming the noise generation mechanism while maintaining the aerodynamic effectiveness of the sharp leading edge
2Object-generated harmful factors
If interference grooves are added to the leading edge, then broadband noise is reduced, but the device complexity increases
Solution Approach 1:
The interference groove structure is segmented into multiple discrete grooves arranged in specific patterns on the leading edge. This segmentation allows the noise reduction function to be achieved through simple geometric features rather than complex continuous structures, making the solution easier to manufacture and implement
Solution Approach 2:
By optimizing specific parameters of the interference grooves (depth ratio, width ratio, spacing), the patent achieves effective noise reduction with relatively simple structural modifications. The parameter optimization ensures that the grooves provide maximum noise suppression with minimal additional complexity
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 design effectively reduces noise levels by changing noise frequencies, achieving a 3.8 dB decrease in maximum broadband noise from 65.0 dB to 61.2 dB at the same operating speed.
Implementation Method 1
air flows impact one another, and air flows impact objects as well, which will result in aerodynamic noise
Implementation Method 2
the maximum value of its broadband noise is generated at the leading edge of the blade
Data Source
AI summary
Disclosed are a centrifugal fan blade assembly and a centrifugal fan, comprising a plurality of blades, a blade leading edge of at least some of the blades being provided with an interference groove, the interference groove extending in a width direction of the blade. By providing the interference groove extending in the width direction of the blade on the blade leading edge, when the fan blade assembly is running, the interference groove changes noise frequency, thereby preventing the blade leading edge from producing a relatively large broadband noise after being impacted by a high speed air flow, thus effectively reducing noise.