Fan Blade Angle Optimization for Noise and Efficiency
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Solution Overview
Problem
Conventional fans suffer from excessive noise, high power consumption, and low static pressure due to overlarge setting angles of blades, leading to flow separation and turbulence, which reduces their efficiency in heat dissipation for electronic devices.
Innovation Solution
The fan design features blades connected to the hub at a reduced angle of 22.5 to 36 degrees, along with a proportional hub and blade ratio, to improve airflow smoothness, reduce noise, and increase static pressure, thereby enhancing efficiency and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the blade setting angle is increased to generate high pressure and large wind volume, then the wind volume increases, but flow separation and turbulence occur causing excessive noise and reduced efficiency
Solution Approach 1:
The patent changes the blade setting angle parameter from the conventional large angle (>40 degrees) to a smaller angle (10 to 30 degrees). This parameter modification eliminates flow separation and turbulence at the blade suction surface, thereby reducing noise generation while maintaining efficient airflow. The specific angle range of 10-30 degrees is optimized to prevent the inflow angle from becoming too large, which would otherwise cause the harmful flow separation phenomenon.
2Stress or pressure
If the blade setting angle is increased to generate high pressure, then the pressure increases, but pressure vibration and noise bandwidth increase
Solution Approach 1:
The patent modifies the blade setting angle parameter to a smaller range (10 to 30 degrees) compared to conventional designs. This parameter change reduces pressure vibration on the blade surface by preventing excessive inflow angles, thereby decreasing noise bandwidth and prominence ratio while still achieving the required pressure generation through optimized blade geometry and proportional hub-blade ratios.
3Productivity
If high electric current is used to drive the fan, then the wind volume increases, but power consumption increases and speed stalls occur early
Solution Approach 1:
The patent changes multiple parameters including blade setting angle (10-30 degrees), hub-blade ratios (0.3-0.7), and blade proportions to optimize the fan's aerodynamic performance. These parameter modifications enable the fan to achieve high wind volume with reduced power consumption by improving airflow efficiency and delaying speed stall occurrence, eliminating the need for excessive electric current.
4Use of energy by moving object
If the blade setting angle is reduced to decrease load and power consumption, then power consumption decreases, but wind volume may be reduced
Solution Approach 1:
The patent optimizes multiple parameters simultaneously: blade setting angle (10-30 degrees), hub-blade ratios (0.3-0.7), and blade geometric proportions. This multi-parameter optimization ensures that reducing the blade angle to decrease load and power consumption does not compromise wind volume, as the combined effect of all parameter adjustments maintains or enhances overall fan performance.
Solution Approach 2:
The patent employs a composite design approach by combining multiple optimized components with specific proportional relationships. The hub and blades are designed with specific proportional ratios, and the blade geometry is optimized in conjunction with the setting angle, creating a composite structural solution that achieves both low power consumption and high wind volume through synergistic parameter combinations.
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 results in a fan with lower power consumption, increased efficiency, and reduced noise, while maintaining high wind pressure and volume, effectively addressing the limitations of conventional fans by optimizing blade angles and ratios.
Implementation Method 1
The motor is connected to the impeller for driving the impeller to rotate
Implementation Method 2
When airflow passes through the blades, an inflow angle is generated. Because the setting angle and the inflow angle are overlarge, flow separation occurs at a suction surface of the blade
Implementation Method 3
The main body has an air inlet, an air outlet and at least one expanding portion connected to the main body and installed at the air inlet or the air outlet so as to increase the airflow
Data Source
AI summary
A fan includes a housing, an impeller and a motor. The housing has a main body, a motor base and at least one supporting member disposed between the main body and the motor base. The impeller is disposed on the motor base and has a hub and a plurality of blades disposed around the hub. The motor is connected to the impeller for driving the impeller to rotate. Each of the blades is connected to the hub at a predetermined angle ranging from 22.5 degrees to 36 degrees.