Fan Blade Ridge Groove Pattern for Noise Reduction
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Solution Overview
Problem
Large-capacity air conditioning systems generate excessive noise due to high air flow rates, which is a problem not adequately addressed by existing fan designs.
Innovation Solution
The fan design incorporates an alternating pattern of ridge and groove parts on the blade rear end, which are rounded and protrude in opposite directions, creating an imaginary extension line from the hub to the blade side end, allowing these parts to be alternately arranged to cancel out noise-causing sound waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the air flow rate of the air conditioning system is increased to achieve high cooling capacity, then the cooling performance is improved, but noise generated by air flow separation on the blade rear surfaces increases
Solution Approach 1:
The blade rear end is segmented into multiple alternating ridge parts and groove parts, creating a periodic structure that divides the air flow path into multiple channels. This segmentation prevents large-scale air flow separation by guiding the air through controlled pathways, thereby reducing noise while maintaining high air flow rates required for large-capacity cooling
Solution Approach 2:
The alternating pattern of ridge and groove parts creates a periodic structure along the blade rear end. This periodic geometry generates periodic air flow patterns that interfere destructively with noise-generating vortices, reducing overall noise emission while allowing sustained high air flow rates for effective cooling performance
2Productivity
If air flows at high speed through the fan to achieve high air flow rate, then the cooling efficiency is improved, but air flow separation occurs on the blade rear surfaces generating noise
Solution Approach 1:
The alternating ridge and groove parts are strategically positioned on the blade rear end where air flow separation typically occurs. This local modification creates zones of different flow characteristics - the groove parts guide air smoothly while the ridge parts generate controlled vortices that cancel noise, thereby maintaining high air flow rate while reducing noise from separation
3Object-generated harmful factors
If the blade design is modified to prevent air flow separation and reduce noise, then noise is reduced, but the structural complexity of the blade increases
Solution Approach 1:
The ridge and groove parts are designed with smooth curved transitions rather than sharp edges, creating a streamlined periodic structure. This curvature approach maintains aerodynamic efficiency while preventing flow separation, achieving noise reduction through geometry rather than complex mechanical structures or additional components
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 design effectively reduces noise generation by ensuring that sound waves produced on the ridge and groove parts are out of phase, resulting in destructive interference and minimized noise output.
Implementation Method 1
The ridge parts and the groove parts are alternately arranged so that sounds generating from air flowing on the ridge parts and the groove parts cancel out each other
Data Source
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AI summary
Provided is a fan. The fan includes a hub and a blade extending from the hub. The blade includes a blade rear end having a predetermined curvature and a blade side end connected to the blade rear end. The blade rear end includes ridge parts protruding in a predetermined direction from an extension and furrow parts protruding in a direction opposite to the predetermined direction.