Axial Flow Fan with Aerodynamic Protrusions

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Solution Overview

Problem

Existing axial flow fans lack enhanced performance in terms of air flow head and aerodynamic efficiency, particularly when used in motor vehicle cooling and heating systems, and are prone to noise and vortical effects that reduce efficiency.

Innovation Solution

The axial flow fan design features a cup-shaped central hub with blades that are inclined and shaped with spiral profiles, equipped with co-planar aerodynamic protrusions and a peripheral band to stabilize the blades and reduce vortical effects, optimizing blade spacing and angles for improved airflow and noise reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional axial flow fans are used, then the structure is simple, but the air flow head and aerodynamic efficiency are insufficient

Engineering Contradiction:
Improveair flow headVSAvoidblade structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The blade is divided into multiple sections with different aerodynamic profiles: a first portion with a first profile and a second portion with a second profile. This segmentation allows each portion to be optimized for its specific function, improving overall air flow head and aerodynamic efficiency while maintaining manageable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the blade are assigned different aerodynamic profiles tailored to their local requirements. The first portion has a first aerodynamic profile optimized for its position, while the second portion has a second aerodynamic profile optimized for its position, creating local quality variations that enhance overall performance

Inventive Principle:
Principle #3Local quality

2Productivity

If conventional fans are used, then manufacturing is easier, but aerodynamic efficiency is reduced due to vortical effects

Engineering Contradiction:
Improveaerodynamic efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The blade features a twisted configuration where the aerodynamic profile changes along the length of the blade. This dynamic variation in profile orientation optimizes airflow patterns, reducing vortical effects and improving aerodynamic efficiency while remaining manufacturable through standard forming processes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The blade incorporates curved aerodynamic profiles and a twisted geometry that smoothly transitions between sections. These curved elements optimize airflow patterns, reduce vortical effects, and improve aerodynamic efficiency while maintaining compatibility with conventional manufacturing methods

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If blades are positioned to maximize air flow, then productivity increases, but noise and vortical effects increase

Engineering Contradiction:
Improveair flow rateVSAvoidnoise and vortical effects
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The blade is segmented into multiple portions with different aerodynamic profiles optimized for their specific positions. This segmentation allows the blade to generate sufficient air flow while controlling vortical effects at different locations, thereby reducing noise without sacrificing productivity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design converts potentially harmful vortical effects into beneficial airflow patterns by strategically positioning and profiling blade sections. The twisted configuration and varied aerodynamic profiles transform what would be harmful vortices into controlled airflow that enhances performance while reducing noise

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 significantly enhances air flow head and aerodynamic efficiency while minimizing noise and vortical effects, resulting in improved fan performance and efficiency.

Implementation Method 1

Each blade (3) extends between a first end (3a) proximal to the hub (2) and a second end (3b), opposite the first, distal from the hub (2)... Each blade (3) has a spiral shape extending from the first end (3a) to the second end (3b)

Methodology Applied
Scientific EffectAerodynamic force: Aerofoil

Implementation Method 2

a plurality of aerodynamic protrusions (11), each connected to a respective blade (3)... The protrusions (11) are co-planar and lie in a plane (PP) perpendicular to the axis of rotation (A) of the fan (1)

Methodology Applied
Scientific EffectVortical effects: Vortex Ring

Data Source

PatentEP2191145B1Axial flow fan
Publication Date: 2017.09.06 SPAL AUTOMOTIVE
  • EP2191145B1 patent drawingFigure 1
  • EP2191145B1 patent drawingFigure 2
  • EP2191145B1 patent drawingFigure 3

AI summary

An axial flow fan comprises a central hub (2) and a plurality of blades (3), each fixed to the central hub (2) and extending from a respective first end (3 a) proximal to the hub (2) to a respective second end (3b) distal from the hub (2); the blades (3) are inclined at a keying angle (ß) to a rotation plane (R) of the fan which also comprises a plurality of aerodynamic protrusions (11), each extending from a first lateral edge (6) of a corresponding blade (3) in the vicinity of its second end (3b); each protrusion (11) lies in a plane (PP) perpendicular to an axis (A) of fan rotation.