Fan Blade Sweep Structure Reduces Tip Low-Speed Region

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Solution Overview

Problem

Conventional fan blades exhibit a low-speed region at the tip portion due to differences in line velocities between the root and tip portions, leading to reduced performance and efficiency.

Innovation Solution

The blade structure incorporates a sweep or spline design on the leading and trailing edge portions, forming a forward sweep or curvature in the inflow direction to reduce low-speed regions at the tip compared to the root portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the blade cross-section is overlapped along the circumference without changing the angle in the radius direction, then the velocity triangle shape is uniform, but a low-speed region occurs at the tip portion due to difference in line velocities between root and tip

Engineering Contradiction:

Improveuniform velocity triangle shapeVSAvoidfluid speed at tip portion

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The blade structure applies different geometric characteristics to different radial positions. The leading edge portion has a different angle relative to the radial direction compared to the trailing edge portion, creating local variations in blade geometry that compensate for the velocity difference between root and tip portions. This local differentiation resolves the low-speed region at the tip while maintaining overall structural coherence.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The blade design introduces asymmetry by setting different angles for the leading edge portion and trailing edge portion relative to the radial direction. This asymmetric configuration creates a sweep structure that adjusts the effective blade angle along the span, compensating for the velocity distribution差异 and eliminating the low-speed region at the tip portion.

Inventive Principle:

Principle #4Asymmetry

2Ease of manufacture

If conventional blade structure is used, then manufacturing is simple, but leakage loss and total pressure loss increase due to low-speed region at tip

Engineering Contradiction:

Improveblade manufacturing simplicityVSAvoidleakage loss and total pressure loss

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The invention modifies the geometric parameters of the blade by defining different angles for the leading edge portion and trailing edge portion relative to the radial direction. This parameter change creates a sweep structure that improves airflow characteristics at the tip portion, reducing leakage loss and total pressure loss while maintaining manufacturability through straightforward angular specifications.

Inventive Principle:

Principle #35Parameter changes

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 reduces leakage loss and total pressure loss, enhancing the efficiency and performance of the fan by improving airflow at the tip portion.

Implementation Method 1

a sweep portion formed in a straight line on at least any one of the leading edge portion or the trailing edge portion in order to reduce a fluid low-speed region at the tip portion compared to the root portion

Methodology Applied

Scientific EffectSweep structure:

Implementation Method 2

a spline portion formed in a curve on at least any one of the leading edge portion or the trailing edge portion in order to reduce a fluid low-speed region at the tip portion compared to the root portion

Methodology Applied

Scientific EffectSpline structure:

Data Source

PatentUS10724537B2Blade structure and fan and generator having same

Publication Date: 2020.07.28 DOOSAN HEAVY IND & CONSTR CO LTD

AI summary

The present disclosure relates to a blade structure and a fan and a generator having the same. In accordance with the present disclosure, there is the effect that can ultimately enhance efficiency of the generator by forming the sweep structure or the spline structure on the blade in the inflow direction side of fluid to reduce a low-speed region around the tip of the blade.