Composite Axial Fan Blade With Trailing Flap for Inner-Span Efficiency
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Solution Overview
Problem
Large diameter axial fans are inefficient due to inner blade sections operating at low tangential speeds, leading to ineffective air flow and energy waste, with limited design flexibility and high production costs hindering aerodynamic optimization.
Innovation Solution
A blade assembly for large diameter axial fans featuring a composite airfoil with a semi-airfoil and aft flap, allowing adjustable deflection and a channel for fluid flow, enhancing aerodynamic performance and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the fan operates at full speed with fixed pitch angle, then the flow rate requirement is met, but the operating point does not coincide with maximum efficiency point causing energy waste
Solution Approach 1:
The patent applies the dynamics principle by making the blade pitch angle adjustable during operation. The control system varies the pitch angle dynamically to move the operating point along the characteristic curve, allowing the fan to operate at maximum efficiency under different flow rate requirements while maintaining productivity.
Solution Approach 2:
The patent implements parameter changes by modifying the pitch angle parameter to optimize performance. By changing the pitch angle, the characteristic curve shifts, allowing the operating point to be adjusted to coincide with the maximum efficiency point while still meeting the required flow rate.
2Use of energy by moving object
If the pitch angle is varied to improve efficiency, then energy efficiency increases slightly, but the characteristic curve still cannot reach maximum efficiency and design flexibility is limited
Solution Approach 1:
The patent overcomes limited design flexibility by implementing a dynamic pitch adjustment mechanism controlled by a control system. This allows continuous variation of the pitch angle during operation, providing adaptability to different operating conditions and enabling the fan to reach maximum efficiency points that were previously inaccessible with fixed pitch designs.
Solution Approach 2:
The patent enhances design flexibility through parameter changes by allowing the pitch angle to be varied continuously rather than being fixed. The control system enables real-time adjustment of this critical parameter, transforming a static design into an adaptive system that can optimize efficiency across different operating scenarios.
3Ease of manufacture
If inner blade sections are simplified for easier construction, then manufacturing cost and complexity are reduced, but the inner sections become mechanically functional only and cannot generate effective air flow
Solution Approach 1:
The patent applies local quality by giving different sections of the blade different functions. The outer sections maintain aerodynamic airfoils for flow generation, while the inner sections use simplified structures with guide surfaces that direct flow onto the outer sections. This localized differentiation allows construction simplicity in inner sections while preserving overall productivity through the collaborative function of all sections.
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 blade assembly improves overall efficiency by stabilizing air flow and aligning the operating point with maximum efficiency, reducing energy consumption and production costs.
Implementation Method 1
between the fore semi-airfoil and the aft flap a channel suitable for allowing a fluid flow from the face to the back of the composite airfoil
Implementation Method 2
a blade, wherein a portion of the blade has a composite airfoil comprising a fore semi-airfoil and an aft flap
Data Source
Figure 1
Figure 2
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AI summary
The invention relates to a blade assembly 30 for a large dimension axial fan 32 having a rotation axis X. The blade assembly of the invention comprises: - a root structure 34 intended to mechanically connect the blade assembly to a hub 36; - a blade, wherein at least one portion of the blade has a composite airfoil 46 comprising a fore semi-airfoil 48 and an aft flap 50, wherein: - the semi-airfoil is intended to be assembled at a predefined pitch angle αc with respect to the hub 36 by means of the root structure; - the flap 50 is mounted on the blade such that it can be fixed in a position comprised between a maximum deflection position and a minimum deflection position with respect to the pitch angle αc; and - between the fore semi-airfoil and the aft flap a channel 54 is defined suitable for allowing a fluid flow from the face v to the back d of the composite airfoil. The invention further relates to a fan comprising a plurality of blades.