Fan Blade Trailing-Edge Vortex Disturbance for AC Noise Reduction
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Solution Overview
Problem
Air conditioning systems experience significant vortex noise due to vortex detachment from fan blades, leading to pulsation and noise generation.
Innovation Solution
An air supply assembly with a fan blade featuring a vortex disturbing structure on its rear edge, accommodated within a straight cylinder-shaped flow guide channel, and a preset gap between the fan blade and the flow guide channel to prevent vortex detachment, reducing noise formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional fan blade design is used, then the air conditioning system can operate, but vortex noise is generated due to vortex detachment from the fan blade
Solution Approach 1:
The patent applies local quality by adding vortex disturbing structures (such as serrated edges or small protrusions) only at specific locations on the fan blade, particularly at the trailing edge where vortex detachment occurs. This localized modification disrupts vortex formation without requiring complete redesign of the entire fan blade, thereby reducing vortex noise while maintaining overall structural simplicity
Solution Approach 2:
The patent implements preliminary action by providing a flow guide member with a preset gap before the vortex can fully detach and cause noise. The flow guide member pre-configures the airflow path and restricts vortex development in advance, preventing the harmful vortex detachment from occurring in the first place
2Object-affected harmful factors
If the fan blade operates without flow guidance, then the structure is simple, but vortex detachment occurs causing pulsation and noise
Solution Approach 1:
The patent introduces a flow guide member as an intermediary component between the fan blade and the surrounding environment. This flow guide member acts as a mediator that shapes and controls the airflow, preventing direct vortex detachment from the fan blade while maintaining a relatively simple overall structure
Solution Approach 2:
The flow guide member is designed with segmented or modular features that can be independently configured. The preset gap and straight cylinder shape are divided into distinct functional zones, allowing each segment to address specific aspects of vortex control without requiring complete structural complexity
3Object-affected harmful factors
If vortex energy is not dispersed, then the flow path is simple, but large-scale low-frequency vortices cause significant noise
Solution Approach 1:
The vortex disturbing structures on the fan blade trailing edge create controlled mechanical disturbances that break up large-scale vortices into smaller eddies. These deliberate vibrations and flow disruptions transform the coherent vortex structures into turbulent fluctuations, converting low-frequency noise into higher-frequency broadband noise that is less perceptible and harmful
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 disperses vortex energy and prevents vortex detachment, significantly reducing aerodynamic noise by cutting large-scale low-frequency vortices into small-scale high-frequency vortices, thereby scattering sound wave energy and minimizing broadband noise.
Implementation Method 1
When an airflow passes through surfaces of fan blades of the air conditioning system, vortices will be generated. A trailing edge of the fan blade is prone to vortex detachment
Implementation Method 2
Periodic vortex detachment will cause changes in the action force exerted by airflow on the object, resulting in vortex noise of fan blade
Implementation Method 3
the preset gap is used to define movement of an airflow formed on the fan blade in a radial direction of the flow guide channel
Data Source
AI summary
The present application provides an air supply assembly, an air conditioner outdoor unit, and an air conditioner. The air supply assembly includes: a fan, which includes at least one fan blade having a rear edge of the fan blade and an outer edge of the fan blade; in which the outer edge of the fan blade is located on a side away from a rotational axis of the fan, and the rear edge of the fan blade is connected to the outer edge of the fan blade; the orientation of the rear edge of the fan blade is opposite to a rotational direction of the fan, and a vortex disturbing structure is provided on the rear edge of the fan blade; and a flow guide member having a flow guide channel; in which the flow guide channel is sleeved on an outer side of the fan.