Blunt Trailing Edge Rotor Blade with Vortex Generators
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Solution Overview
Problem
Existing wind turbine rotor blade profiles with large relative thickness suffer significant reduction in lift coefficient and poor aerodynamic performance under turbulent flow conditions, leading to unfavorable design angles and structural limitations.
Innovation Solution
Incorporation of at least one vortex generator on the suction side of the rotor blade with a blunt trailing edge, positioned between 15% and 70% of the chord length, to enhance lift coefficients and lift/drag ratios, allowing for greater aerodynamic angles of attack and reduced rotor blade twist.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a profile of large relative thickness is used to provide structural stability and good body contour, then the structural integrity and spacing of main girders are improved, but the lift coefficient collapses significantly under turbulent flow conditions and the aerodynamic angle of attack changes unfavorably
Solution Approach 1:
The invention changes the geometric parameters of the airfoil profile by implementing a blunt trailing edge with specific thickness ratios (trailing edge thickness between 10-30% of chord length, maximum thickness between 15-25% of chord length). These parameter modifications allow the profile to maintain structural stability while improving aerodynamic performance in turbulent flow, preventing the collapse of lift coefficient that occurs with conventional thick profiles.
Solution Approach 2:
The invention applies local quality by specifically modifying the trailing edge region of the profile while maintaining other portions of the airfoil. The blunt trailing edge geometry is applied locally at the rear portion of the blade, allowing the rest of the profile to maintain its aerodynamic shape while the trailing edge provides enhanced performance in turbulent conditions through its specialized geometry.
2Length of moving object
If the angle of attack is reduced to maintain small blade depths, then the structural dimensions are controlled, but the lift coefficient in the dirty state diminishes to a fraction of the clean value
Solution Approach 1:
The invention changes the operating parameters by enabling the use of higher angles of attack (up to 25 degrees or more) that would normally be avoided in conventional designs. The modified blunt trailing edge geometry allows the airfoil to maintain attached flow and high lift coefficients at these elevated angles, thereby allowing blade designs with greater depths that can achieve higher lift without the severe performance degradation in dirty conditions.
3Reliability
If a thick trailing edge is used to achieve large lift coefficients, then the maximum lift coefficient is improved in clean state, but the lift/drag ratio deteriorates and the maximum thickness becomes excessively large
Solution Approach 1:
The invention optimizes the geometric parameters by limiting the trailing edge thickness to 10-30% of the chord length and the maximum thickness to 15-25% of the chord length. These parameter ranges are carefully selected to achieve an optimal balance: thick enough to generate high lift coefficients but thin enough to maintain favorable lift/drag ratios and avoid excessive blade depth. This resolves the contradiction by finding the optimal parameter window that satisfies both requirements.
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 solution achieves high lift coefficients exceeding 3.0 and significantly improves lift/drag ratios, reducing rotor blade weight and enabling larger rotor diameters while maintaining high efficiency, with vortex generators positioned optimally to mix the boundary layer and delay flow separation.
Implementation Method 1
at least one vortex generator is disposed, in a region of the profile, on the suction side of the rotor blade
Implementation Method 2
with the trailing edge of the profile being blunt, and with the thickness of the trailing edge being between 15% and 70% of the chord length
Data Source
AI summary
A rotor blade (5) of a wind turbine, which has a profile (1-4) having an upper side (suction side) (7) and an underside (pressure side) (8). The profile (1-4) includes a camber line (21, 25) and a chord (18) between a leading edge (10) and a trailing edge (11) of the profile (1-4). The profile (1-4) has a relative profile thickness of more than 45%. At least one vortex generator (50, 50′, 50″, 50′″) is disposed, in the region of the profile (1-4), on the suction side (7) of the rotor blade (5). The profile (1-4) is provided with a blunt trailing edge. And, The thickness of the trailing edge is between 15% and 70% of the chord length.