Swallow Tail Airfoil Trailing Edge Cavity for Wind Turbine Drag Reduction
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Solution Overview
Problem
Existing aerodynamic solutions for wind turbine blades with flat-back airfoils, such as active flow control devices and split plates, increase complexity and costs due to the need for additional components and maintenance, while also introducing noise and drag issues at the root region.
Innovation Solution
The implementation of a swallow tail shaped cavity body attached to the trailing edge of the airfoil, comprising a first and second member forming a non-symmetrical profile, which reduces noise, drag, and flow unsteadiness by smoothing airflow separation, and can be adjusted actively using a movable second member with an actuator for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If active flow control devices like micro-tabs, synthetic jets and micro-flaps are used, then drag is reduced, but device complexity and maintenance cost increase
Solution Approach 1:
The invention extracts the flow control function from complex active devices and implements it through a simple geometric modification - a cut-out section at the trailing edge. This passive geometric feature replaces the need for active components like micro-tabs and synthetic jets, achieving drag reduction without the associated complexity and maintenance requirements.
Solution Approach 2:
The cut-out trailing edge modification represents a simple, inexpensive geometric change that can be easily manufactured and integrated into the airfoil structure. Unlike expensive active flow control systems requiring actuators and control systems, this passive modification is cost-effective and requires no maintenance.
2Object-generated harmful factors
If split plates are applied at the trailing edge, then airflow is modified, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention merges the flow control function with the trailing edge structure itself. Instead of adding separate split plates as additional components, the cut-out section is integrated directly into the trailing edge geometry, simplifying manufacturing while achieving the desired flow modification and reduction of flow unsteadiness.
3Strength
If blunt trailing edge airfoils are used, then structural requirements are met, but noise and drag increase at the root region
Solution Approach 1:
The invention applies local quality modification by introducing a cut-out section specifically at the trailing edge region. This localized geometric change affects the flow characteristics and noise generation at the root region while preserving the overall blunt trailing edge structure that provides the necessary structural integrity.
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 design enhances aerodynamic performance by reducing noise, base drag, and flow unsteadiness while maintaining structural integrity, with simplified assembly and reduced maintenance costs, and can be adapted to existing airfoils or implemented during production.
Implementation Method 1
smoothing airflow separation
Implementation Method 2
reduce e.g. drag
Data Source
Figure 1~3
AI summary
Aerodynamic element having a cross section in an airflow direction with a trailing edge (10c). The aerodynamic element (10) further comprises a non-symmetrical swallow tail shaped cavity body (1, 2) attached to the trailing edge (10c) of the aerodynamic element (10).The aerodynamic element (10) is e.g. applied in a rotor blade for a wind turbine.