Blower Fan Vane Air Gap Gradient for Turbulence Reduction
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Solution Overview
Problem
Conventional blower fans experience reduced input air and increased turbulence and noise due to reverse air currents and interference between air flows, leading to decreased output air and elevated noise levels.
Innovation Solution
The blower fan design features air gaps between the vanes and the housing with varying widths from 0.3 mm to 2.0 mm, narrowing towards the air input portion to prevent reverse air flow and turbulence, and an enclosing plate with air gaps between the bottom and housing to reduce wind shear noise, ensuring unobstructed flow paths for increased input and output air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air gaps are formed between the vanes and the top of the housing to avoid friction and collision, then the reliability of the blower fan is improved, but reverse air flow occurs through the air gaps, causing turbulence and reducing the amount of input air
Solution Approach 1:
The air gap width is made non-uniform, with the narrowest width positioned at the air input portion of the upper edge of each vane. This local variation in gap width creates a flow restriction that prevents reverse air flow while maintaining reliable operation throughout the blower fan system.
2Device complexity
If air gaps are formed between the vanes and the top of the housing to avoid friction or collision, then the device complexity is reduced, but turbulence is produced at the air inlet and wind shear noises are increased
Solution Approach 1:
The air gap width is varied locally, being narrowest at the air input portion adjacent to the air inlet. This localized geometric feature controls the airflow pattern, preventing turbulence and reducing wind shear noises generated at the air inlet without requiring additional components.
3Ease of manufacture
If the air gap width is uniform to simplify manufacturing, then the ease of manufacture is improved, but reverse air flow and turbulence occur, reducing productivity
Solution Approach 1:
The air gap width is designed with a specific gradient, being narrowest at the air input portion and increasing toward other portions. This local variation in geometry optimizes airflow characteristics and prevents reverse flow, thereby increasing the amount of output air without significantly complicating the manufacturing process.
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 suppresses reverse air currents, reduces turbulence and noise, and enhances the overall amount of input and output air by preventing reverse air flow and guiding air smoothly through the fan, thereby improving efficiency and reducing noise.
Implementation Method 1
a flow path formed between the upper edges of the vanes and the top of the housing narrows toward the air input portion, air is not liable to flow reversely to the air inlet for, hence, avoiding turbulence formed at the air inlet adjacent to the air input portion
Implementation Method 2
an air gap being formed between the lower surface and the bottom of the housing, and various widths of the air gap ranging from 0.3 to 2.0 mm while the shortest width is formed between the lateral edge of the lower surface and the bottom of the housing for, thus, avoiding turbulence formed between the enclosing plate and the bottom of the housing, and reducing the wind shear noises
Data Source
AI summary
A blower fan includes a housing having a compartment. A stator and an impeller are mounted in the compartment. The housing further includes an air inlet and an air outlet both communicated with the compartment. The impeller has a hub and a plurality of vanes coupled to the hub. Each vane includes an upper edge whose end is an air input portion adjacent to the air inlet of the housing, and an air gap is formed between the upper edge of each vane and a top of the housing, with various widths of the air gap ranging from 0.3 mm to 2.0 mm, while a shortest width of the air gap is formed between the air input portion of the upper edge and the top of the housing for providing reduced turbulence and noises.