Tandem Tip-Joined Rotor Blade Passive Pitch Control
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Solution Overview
Problem
Existing rotor blade systems for wind turbines require active pitch angle control, which complicates the system, increases weight, and raises costs, while also failing to efficiently adapt to varying wind conditions, including high-wind scenarios.
Innovation Solution
A tandem tip-joined rotor blade system where a leading airfoil is uncoupled from the hub's rotational movement and connected to a trailing airfoil via a connector, allowing for passive pitch angle control and adaptation to wind conditions through the interaction of their quarter-chords and gravitational forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If active pitch control devices are used to adjust rotor blade pitch angle, then aerodynamic efficiency is improved, but system complexity increases
Solution Approach 1:
The rotor blade system performs pitch angle adjustment automatically through gravitational forces and aerodynamic interactions between the two airfoils, without requiring external active control devices. The uncoupled airfoil naturally responds to gravity and wind conditions, while the coupled airfoil follows hub rotation, creating passive pitch control that adapts to varying wind conditions.
Solution Approach 2:
The system transitions from a static, fixed-pitch blade design to a dynamic, adaptive pitch system by allowing the uncoupled airfoil to rotate independently relative to the hub. This dynamic configuration enables the blade to automatically adjust its pitch angle in response to changing wind conditions, gravitational forces, and aerodynamic loads during rotation.
2Adaptability or versatility
If active pitch control devices are coupled to rotor blades, then pitch angle adjustment capability is improved, but rotor blade weight increases
Solution Approach 1:
The rotor blade system performs pitch angle adjustment automatically through gravitational forces and aerodynamic interactions between the two airfoils, without requiring external active control devices. The uncoupled airfoil naturally responds to gravity and wind conditions, while the coupled airfoil follows hub rotation, creating passive pitch control that adapts to varying wind conditions.
Solution Approach 2:
The invention removes active pitch control devices from the rotor blade system entirely, extracting the problematic components that add weight and complexity. Instead, it uses the inherent physical properties of the dual airfoil configuration and gravitational forces to achieve pitch control, eliminating the need for motors, sensors, and control systems.
3Device complexity
If traditional rotor blade design is used, then structural simplicity is maintained, but adaptability to varying wind conditions deteriorates
Solution Approach 1:
The system transitions from a static, fixed-pitch blade design to a dynamic, adaptive pitch system by allowing the uncoupled airfoil to rotate independently relative to the hub. This dynamic configuration enables the blade to automatically adjust its pitch angle in response to changing wind conditions, gravitational forces, and aerodynamic loads during rotation.
Solution Approach 2:
The rotor blade system performs pitch angle adjustment automatically through gravitational forces and aerodynamic interactions between the two airfoils, without requiring external active control devices. The uncoupled airfoil naturally responds to gravity and wind conditions, while the coupled airfoil follows hub rotation, creating passive pitch control that adapts to varying wind conditions.
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 simplifies pitch angle control, reduces complexity and cost, decreases blade fatigue and noise, and prevents turbine damage by passively controlling pitch angles and inducing stall conditions in high winds, enhancing overall wind turbine performance.
Implementation Method 1
passive pitch angle control and adaptation to wind conditions through the interaction of their quarter-chords and gravitational forces
Implementation Method 2
The first airfoil having a quarter-chord defined along a span of the first airfoil is coupled to the hub, but is uncoupled from the rotational movement of the hub
Data Source
AI summary
A rotor blade system includes a hub for rotational movement in a defined direction of rotation. A first airfoil having a quarter-chord defined along a span thereof is coupled to the hub, but is uncoupled from the rotational movement of the hub. A second airfoil having a quarter-chord defined along a span thereof is coupled to the hub for rotation in direct correspondence with the rotational movement of the hub. The quarter-chord of the first airfoil leads the quarter-chord of the second airfoil when the hub experiences its rotational movement in the defined direction of rotation. A connector couples the tip of the first airfoil to the tip of the second airfoil.