Wind Turbine Rotor Blade Profile Below Chord Skeleton
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Solution Overview
Problem
Existing rotor blade profiles, such as the FX 77-W-500, exhibit a significant drop in lift coefficient and poor aerodynamic properties in turbulent flow, leading to reduced lift and glide ratios, which is unfavorable for wind turbines, and result in increased blade weight and structural constraints due to thick trailing edges.
Innovation Solution
A rotor blade profile with a skeleton line positioned below the chord in sections between 0% and 60% of the profile depth, achieving a relative profile thickness greater than 49% with a thickness reserve less than 35%, allowing for high lift coefficients and glide ratios, and minimizing torsion and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a profile with high relative thickness (e.g., FX 77-W-500 with 50% thickness) is used, then the profile can maintain acceptable lift coefficient when clean, but the maximum lift coefficient drops significantly in turbulent flow and the angle of attack for maximum lift changes significantly
Solution Approach 1:
The patent modifies the profile geometry parameters, specifically positioning the skeleton line below the chord in the front section (0-60% of profile depth) and adjusting the thickness distribution. This creates a profile with relative thickness >49% and thickness reserve <35%, which maintains high lift coefficients in both laminar and turbulent flows while keeping the angle of attack for maximum lift relatively stable
2Strength
If the skeleton line is positioned above the chord (as in conventional profiles), then the profile achieves good lift coefficients, but the thickness reserve becomes too large which reduces the distance between main chords and increases blade weight
Solution Approach 1:
The patent inverts the conventional skeleton line positioning by placing it below the chord in the front section (0-60% of profile depth) rather than above the chord. This inversion reduces the thickness reserve to less than 35%, allowing greater distance between main chords and reducing blade weight while maintaining high lift coefficients through the optimized camber distribution
3Strength
If the maximum profile thickness is positioned at 80% of profile length (as in FX 83-W-500), then the profile achieves high lift coefficients in turbulent flow, but the glide ratio deteriorates and the structural efficiency is reduced
Solution Approach 1:
The patent optimizes the longitudinal position of maximum thickness by positioning it at 25-40% of the profile length rather than at 80%. Combined with the skeleton line positioned below the chord in the front section, this creates a more efficient thickness distribution that maintains high lift coefficients in turbulent flow while improving the glide ratio and structural efficiency
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 proposed profile design maintains high aerodynamic performance in both laminar and turbulent flows, reduces blade torsion, and allows for maximum chord spacing without twisting, resulting in lighter and more efficient rotor blades.
Implementation Method 1
maintains high aerodynamic performance in both laminar and turbulent flows
Implementation Method 2
maintains high aerodynamic performance in both laminar and turbulent flows
Data Source
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AI summary
The invention relates to a profile (1-4) of a rotor blade (5) of a wind power plant. The profile (1-4) according to the invention is characterized in that the skeleton line runs at least in segment below the chord in the direction of the pressure side (8). The profile according to the invention is further characterized in that the profile (1-4) comprises a relative profile thickness of greater than 45% at an airfoil thickness of less than 50%, wherein a lift coefficient (ca) of greater than 0.9, particularly greater than 1.4, is achieved in turbulent flow.