Vortex Generator Fin Camber Variation for Wind Turbine Blades
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Solution Overview
Problem
Existing vortex generators for wind turbine blades face challenges in achieving sufficient separation suppression due to the occurrence of crossflows caused by large camber ratios at the fin tip, which impairs the generation of longitudinal vortices and reduces the aerodynamic performance.
Innovation Solution
The vortex generator features fins with a maximum camber ratio that decreases from the root towards the tip, along with specific geometric configurations such as a chord length ratio of 2.0≤L/H≤4.0 and a platform portion with a curved convex cross-sectional shape, to suppress crossflows and enhance the separation suppressing effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a fin airfoil with a camber is used to increase lift and form longitudinal vortices, then the separation suppressing effect is enhanced, but a crossflow occurs from the fin root to the fin tip due to pressure gradient, which impairs vortex generation
Solution Approach 1:
The patent applies local quality by varying the camber ratio along the height of the fin. The maximum camber ratio is set to be 0.05 or more and 0.20 or less in the lower portion (0-0.5H from root), and 0.03 or more and 0.15 or less in the upper portion (0.5H-H from root). This local differentiation allows the fin to generate sufficient lift in the lower portion while suppressing crossflow in the upper portion, thereby resolving the contradiction between lift generation and crossflow suppression.
2Force
If a relatively large camber is used at the fin tip portion, then lift is increased, but a pressure decrease occurs on the suction surface at the fin tip, causing crossflow that opposes longitudinal vortex generation
Solution Approach 1:
The patent implements local quality by specifying different camber ratio ranges for different height portions of the fin. The lower portion (0-0.5H) has a maximum camber ratio of 0.05-0.20 to generate lift, while the upper portion (0.5H-H) has a maximum camber ratio of 0.03-0.15 to suppress pressure decrease and crossflow. This local differentiation stabilizes the flow pattern by preventing crossflow-induced vortex disruption while maintaining sufficient lift generation.
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 configuration effectively suppresses crossflows, stabilizes the generation of longitudinal vortices, and improves the aerodynamic force and separation suppressing effect of the vortex generator, leading to enhanced wind turbine blade performance.
Implementation Method 1
A vortex generator produces a longitudinal vortex with a lift generated by a fin, to promote momentum exchange inside and outside a boundary layer
Implementation Method 2
promote momentum exchange inside and outside a boundary layer at a wake side of the vortex generator and to reduce the thickness of a boundary layer
Implementation Method 3
suppressing separation at a trailing edge side of a wind turbine blade
Implementation Method 4
A vortex generator produces a longitudinal vortex with a lift generated by a fin
Implementation Method 5
promote momentum exchange inside and outside a boundary layer
Data Source
AI summary
A vortex generator for a wind turbine blade includes at least one fin including a suction surface and a pressure surface. Each of the at least one fin is configured such that, in at least a part of a height range of the fin, a maximum camber ratio cmax/C being a ratio of a maximum camber cmax to a fin chord length C decreases with distance from a root of the fin toward a tip portion of the fin.