Flow Guiding Ring Cavity for Axial Fan Noise Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for reducing pneumatic noise in axial flow fans, such as adding concave grooves to the flow guiding ring, increase the leakage space and reduce fan efficiency by decreasing air outflow, which is not desirable.

Innovation Solution

A flow guiding ring structure with a closed cavity and through holes at the minimum diameter position, allowing airflow to enter the cavity and balance static pressure, reducing turbulence and noise while maintaining air volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If concave circumferential groove structures are added to the flow guiding ring to increase the gap between the flow guiding ring and blade top, then pneumatic noise is reduced, but the air outflow amount and fan efficiency decrease

Engineering Contradiction:
Improvepneumatic noiseVSAvoidair outflow amount
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

A flow guiding ring is introduced as an intermediary component between the blade top and the outer casing. This ring structures the airflow passage and controls the gap distribution, allowing noise reduction through optimized flow guidance while maintaining adequate air outflow. The flow guiding ring acts as a mediator that reconciles the conflict between noise reduction and airflow performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes specific parameters of the flow guiding ring including the gap distance between the ring and blade top (5-15mm), the outer diameter of the ring, and the cross-sectional shape of the airflow passage. By carefully adjusting these parameters, the system achieves noise reduction while preserving fan efficiency and air outflow performance.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the gap between the flow guiding ring and blade top is increased to reduce noise, then pneumatic noise is reduced, but fan efficiency decreases

Engineering Contradiction:
Improvepneumatic noiseVSAvoidfan efficiency
Core Design Contradiction:
Object-generated harmful factorsVSPower

Solution Approach 1:

The patent optimizes the gap parameter between the flow guiding ring and blade top within a specific range (5-15mm). This parameter optimization allows the system to reduce noise through improved flow guidance while avoiding excessive gap sizes that would compromise fan efficiency and power performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The flow guiding ring creates localized flow control at critical areas where noise is generated (blade top region). By improving flow quality locally at the noise source rather than increasing the overall gap uniformly, the system achieves noise reduction while maintaining fan efficiency.

Inventive Principle:
Principle #3Local quality

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 proposed solution effectively reduces noise without decreasing air volume by balancing static pressure and dissipating turbulent energy, enhancing the performance of axial flow fans and air conditioners.

Implementation Method 1

a static pressure returned by each opening is able to be automatically balanced and comprehensively processed inside a annular cavity, and a comprehensive value is finally achieved, that is, the imbalance of the circumferential static pressure of a flow guiding ring may be adjusted, the circumferential turbulence of the airflow in the flow guiding ring is reduced

Methodology Applied
Scientific EffectTurbulence dissipation: Turbulence

Implementation Method 2

a static pressure returned by each opening is able to be automatically balanced and comprehensively processed inside a annular cavity

Methodology Applied
Scientific EffectPressure balancing: Pressure Gradient

Data Source

PatentEP3530961B1Flow guiding ring structure, axial flow fan and air-conditioner
Publication Date: 2024.01.03 GREE ELECTRIC APPLIANCE INC OF ZHUHAI
  • EP3530961B1 patent drawingFigure 1~2
  • EP3530961B1 patent drawingFigure 3~4
  • EP3530961B1 patent drawingFigure 5

AI summary

Disclosed are a flow guiding ring structure, an axial flow fan and an air conditioner, relating to the field of noise reduction, and used for reducing the pneumatic noise of the axial flow fan during use on the premise of guaranteeing the air outflow amount of the fan. The flow guiding ring structure includes a ring body (1). The ring body (1) includes a closed cavity (11) and a through hole (12). A minimum diameter position of the ring body (1) is provided with an opening (13). The cavity (11) communicates with the through hole (12) via the opening (13). A fluid in the through hole (12) is able to enter the cavity (11) through the opening (13). According to the above technical solutions, on the premise of guaranteeing the Venturi tube effect of the flow guiding ring structure, an opening structure is added on a surface, and turbulent energy of a blade top airflow is transmitted out of a fan area in a radial direction, so that the aim of noise reduction is achieved.