Pressure Side Winglet for Wind Turbine Blade Tip Losses
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Solution Overview
Problem
Conventional winglets for wind turbine rotor blades do not significantly enhance performance and efficiency, often reducing clearance between blades and towers, and are primarily designed to reduce noise rather than improve energy output.
Innovation Solution
A pressure side winglet with a unique geometric shape defined by specific design parameters such as spanwise radius, chord, sweep, pre-bend, twist angle, and cant angle, which improves aerodynamic efficiency and reduces tip losses by enhancing vortex displacement without increasing loads or rotor diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional suction side winglets are used, then noise is reduced, but clearance between rotor blades and tower decreases
Solution Approach 1:
The patent inverts the conventional winglet configuration by placing the winglet on the pressure side instead of the suction side. This reversal maintains noise reduction benefits while preserving blade-to-tower clearance, as the pressure side winglet geometry does not encroach into the clearance space in the same manner as suction side winglets.
Solution Approach 2:
The patent modifies key geometric parameters of the winglet including sweep angle (10-30 degrees), cant angle (10-30 degrees), and spanwise distribution. These parameter changes optimize the winglet's aerodynamic performance while controlling its physical footprint to maintain adequate clearance between rotating blades and the stationary tower structure.
2Object-affected harmful factors
If conventional winglets are used, then noise is reduced, but overall performance and efficiency are not improved
Solution Approach 1:
The pressure side winglet design achieves multi-functionality by simultaneously reducing noise and improving energy output. The winglet geometry is optimized to perform both noise mitigation and aerodynamic enhancement, making it a universal solution that addresses multiple performance requirements rather than just noise reduction.
Solution Approach 2:
The patent optimizes specific geometric parameters including chord length (0.5-2.0% of rotor radius), spanwise distribution, and cross-sectional shape to enhance power coefficient and aerodynamic efficiency. These parameter adjustments are designed to improve energy capture while the winglet maintains its noise reduction function.
3Productivity
If rotor diameter is increased to improve energy output, then power coefficient increases, but loads and costs increase
Solution Approach 1:
The patent applies local quality optimization by adding a winglet at the blade tip region rather than increasing the overall rotor diameter. This localized modification improves aerodynamic efficiency and energy output at the critical tip region where losses occur, without proportionally increasing the structural loads and costs associated with a larger rotor diameter.
Solution Approach 2:
Instead of increasing energy output by expanding in one dimension (rotor diameter), the patent adds a third-dimensional feature (the winglet extending from the blade tip). This dimensional addition improves aerodynamic performance and energy capture without requiring proportional increases in rotor size and associated loads.
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 winglet design increases annual energy production of wind turbines while maintaining clearance and reducing costs by enhancing power coefficient and aerodynamic performance without increasing loads or rotor diameter.
Implementation Method 1
improves aerodynamic efficiency and reduces tip losses by enhancing vortex displacement
Implementation Method 2
The rotor blades capture kinetic energy from wind using known airfoil principles and transmit the kinetic energy through rotational energy
Data Source
AI summary
In one aspect, a winglet for a rotor blade is disclosed. The winglet may generally include a winglet body extending at least partially between a winglet origin and a blade tip. The winglet body may define a sweep and a pre-bend. The sweep defined between the winglet origin and the blade tip may range from about 0.5% to about 4.0% of a span of the rotor blade. The pre-bend defined between the winglet origin and the blade tip may range from about 1.5% to about 4.5% of the span of the rotor blade.