Forward Curved Fan Blade With Varying Edge Angles
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Solution Overview
Problem
Existing forward curved centrifugal fan blades with constant inner diameter and blade angles suffer from inefficiencies due to non-uniform air intake across the blade span, leading to reduced performance and increased noise.
Innovation Solution
The design incorporates fan blades with a first portion having constant leading and trailing edge angles, while the second and third portions have varying angles and inner radii, maintaining constant chord length and blade solidity, allowing for uniform air intake and improved airflow distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If constant inner diameter and constant blade angles are used, then manufacturing is simplified, but air intake uniformity and efficiency deteriorate
Solution Approach 1:
The blade is divided into three portions along the spanwise direction, with the first portion having constant leading and trailing edge angles, and the second and third portions having varying angles and inner radii. This local differentiation allows each section to be optimized for its specific function: the first portion maintains manufacturing simplicity while the second and third portions improve air intake uniformity across the blade span.
2Ease of manufacture
If constant blade angles are used, then manufacturing is easier, but efficiency and noise performance worsen
Solution Approach 1:
Different blade portions have different angle characteristics: the first portion maintains constant angles for ease of manufacture, while the second and third portions feature varying leading and trailing edge angles to optimize airflow and reduce noise, thereby improving overall fan efficiency without compromising manufacturing feasibility.
Solution Approach 2:
The blade is segmented into three distinct portions along the spanwise direction, allowing independent optimization of each section. This segmentation enables the combination of constant angles in the first portion for manufacturing ease with varying angles in the second and third portions for enhanced efficiency and noise reduction.
3Device complexity
If constant inner radius is used, then manufacturing is simplified, but airflow distribution deteriorates
Solution Approach 1:
The inner radius is kept constant in the first portion of the blade for manufacturing simplicity, while varying in the second and third portions to improve airflow distribution. This localized variation allows the blade to achieve better aerodynamic performance without significantly increasing overall geometric complexity.
Data Source
AI summary
A fan blade for a fan impeller is coupled to a front endring and a rear endring. The fan blade includes a first portion, a second portion, a third portion, a leading edge, and a trailing edge. The second portion is positioned on a first side of the first portion. The third portion is positioned on a second side of the first portion. The leading edge defines a leading edge blade angle and the trailing edge defines a trailing edge blade angle. The leading edge blade angle and the trailing edge blade angle are constant within the first portion and the leading edge blade angle and the trailing edge blade angle vary within the second portion and the third portion.