Axial Flow Vane Wavy Stacking Line Reduces Secondary Flow Losses
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Solution Overview
Problem
Conventional three-dimensionally designed vanes with simple curved stacking lines fail to effectively reduce local peaks of secondary flow losses in regions near the hub and tip portions of axial flow fans, compressors, and turbines.
Innovation Solution
A method for designing vanes with a base vane formed by stacking airfoil-shaped profiles along a smooth curved or straight line, where the stacking line is modified to a wavy curved line in the axial direction, particularly in the hub and tip regions, to prevent flow separation and reduce secondary flow losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If simple curved stacking lines (arc or smooth curved line) are used in three-dimensional vane design, then secondary flows are suppressed at a macro level, but local peaks of secondary flow losses in hub and tip regions cannot be reduced
Solution Approach 1:
The patent applies local quality by differentiating the stacking line design between different radial regions. The stacking line comprises a hub region stacking line for the hub region and a tip region stacking line for the tip region, allowing each region to have optimized curvature characteristics. This enables local reduction of secondary flow losses in hub and tip regions while maintaining overall flow suppression, resolving the contradiction between energy loss reduction and design complexity.
2Ease of manufacture
If conventional three-dimensional vane design with smooth curved stacking lines is used, then the design is simple and manufacturable, but it fails to reduce peak secondary flow losses in local regions
Solution Approach 1:
The patent segments the stacking line into multiple portions: a hub region stacking line and a tip region stacking line, each with different curvature characteristics. This segmentation allows independent optimization of each region to reduce local secondary flow losses while maintaining overall manufacturing feasibility. The segmented approach resolves the contradiction by enabling region-specific loss reduction without requiring complete redesign of the entire vane.
3Loss of energy
If the stacking line is modified to reduce local secondary flow losses, then energy efficiency improves, but the design complexity and calculation requirements increase
Solution Approach 1:
The patent employs parameter changes by defining specific curvature radius ratios for different stacking line portions. The hub region stacking line has a curvature radius ratio within 0.05-0.15, while the tip region stacking line has a curvature radius ratio within 0.10-0.20. These quantified parameter ranges provide a systematic design methodology that reduces local secondary flow losses through controlled geometric modifications, balancing energy efficiency improvement with manageable design complexity.
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 method significantly reduces peak secondary flow losses by approximately 3.4% in local secondary flow regions, improving the efficiency of fluid flow through inter-vane passages.
Implementation Method 1
Because of having the above-mentioned shape, in the three-dimensionally designed vane, new vortices are generated in an intended mode in flows in the inter-vane flow passages of the conventional two-dimensionally designed vane, thus suppressing the secondary flows.
Implementation Method 2
flows in the vicinity of the solid wall are different from the ideal flows due to influence of viscosity, that is, secondary flows are generated
Data Source
AI summary
Provided are a method for designing a vane, which can reduce peaks of secondary flow losses appearing locally in secondary flow regions and a vane obtained by the designing. The method for designing a vane includes: a step of determining a base vane formed by stacking profiles having airfoil shapes in a spanwise direction along a stacking line which is configured as a smooth curved line having no inflection point or a straight line; and a step of changing the stacking line of the base vane to a smooth wavy curved line which waves in an axial direction of a fan, a compressor or a turbine and has no elbows.