Cylindrical Wind Turbine Rotor Torque Limiting
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Solution Overview
Problem
Wind turbines are vulnerable to damage in high winds and produce low power in low wind speeds due to aerodynamic lift increases with wind speed, and existing control mechanisms are complex and heavy, increasing manufacturing costs and installation complexity.
Innovation Solution
A wind turbine assembly with a cylindrical rotor featuring aerofoil blades arranged closely around the rotational axis, where the leading edges are farther from the axis than the trailing edges, and the blades are angled to face outward and inward, reducing the need for separate flow regulators or shutters, and allowing for increased blade density for higher inertia and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If control mechanisms (control electronics, braking systems, shuttering elements) are added to limit rotor speed in high winds, then wind turbine reliability in high wind conditions improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent converts the harmful effect of high wind loads into a beneficial self-regulating mechanism. When wind speed exceeds a threshold, the rotor automatically transitions from lift-dominated to drag-dominated operation, and the closely spaced blades create mutual interference that limits torque. This eliminates the need for complex control electronics, braking systems, or shuttering mechanisms while maintaining reliability in high wind conditions.
Solution Approach 2:
The wind turbine design enables self-regulation of rotor speed and torque through its geometric configuration. The closely spaced aerofoil blades (with separation less than chord length) automatically create flow interference and torque limiting effects at high speeds without requiring external control systems. The system serves itself by using its own structure to regulate its operation.
2Object-affected harmful factors
If flow regulator mechanisms are added to reduce wind flow through the rotor in high winds, then wind turbine damage vulnerability decreases, but manufacturing complexity and weight increase
Solution Approach 1:
The patent extracts and eliminates the flow regulator mechanism entirely from the system. Instead of adding a variable flow regulator to reduce wind flow through the rotor, the design uses the inherent aerodynamic characteristics of closely spaced blades to automatically limit torque and power extraction at high wind speeds. This removes the complex mechanical flow control system while achieving the same protective function.
3Reliability
If robust engineering is applied to flow regulator mechanisms to withstand mechanical demands, then wind turbine reliability improves, but weight increases and installation complexity increases
Solution Approach 1:
The wind turbine design enables self-regulation of rotor speed and torque through its geometric configuration. The closely spaced aerofoil blades (with separation less than chord length) automatically create flow interference and torque limiting effects at high speeds without requiring external control systems. The system serves itself by using its own structure to regulate its operation.
Solution Approach 2:
The patent converts the harmful effect of high wind loads into a beneficial self-regulating mechanism. When wind speed exceeds a threshold, the rotor automatically transitions from lift-dominated to drag-dominated operation, and the closely spaced blades create mutual interference that limits torque. This eliminates the need for complex control electronics, braking systems, or shuttering mechanisms while maintaining reliability in high wind conditions.
4Ease of manufacture
If aerofoil blades are arranged with larger separation for easier manufacture, then manufacturing complexity decreases, but torque limitation capability in high winds is reduced
Solution Approach 1:
The patent applies a specific local geometric condition to the blade arrangement: the separation between adjacent blades is made less than the chord length of the blades. This local quality constraint creates the necessary aerodynamic interference effect that limits torque at high wind speeds. The precise spacing creates flow interaction between blades that automatically regulates power extraction without requiring complex control systems.
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 automatically limits torque at high wind speeds, reduces brake requirements, stabilizes rotational speed, and increases power output at low wind speeds without additional moving parts, enhancing the turbine's reliability and reducing manufacturing and installation complexities.
Implementation Method 1
aerodynamic lift of an aerofoil increases approximately quadratically with relative wind speed
Implementation Method 2
the minimum separation (S) between the leading edge of a first aerofoil and the suction surface of an adjacent aerofoil is less than the chord length (LC)
Data Source
AI summary
A wind turbine assembly comprising a generally cylindrical wind turbine rotor that is supported by a rotor support and operable to rotate about a rotational axis, the rotor comprising a plurality of aerofoil blades with each aerofoil blade having a leading edge, a trailing edge, a suction surface, a pressure surface, and an aerofoil chord having a chord length between the leading edge and the trailing edge, the aerofoil blades being in a generally cylindrical arrangement around the rotational axis with the leading edges at a larger radial separation from the rotational axis than the trailing edges, and the chords being angled relative to radii through the rotational axis such that the suction surfaces and pressure surfaces respectively face generally outwardly and inwardly from and to the rotational axis, wherein the minimum separation (S) between the leading edge of a first aerofoil and the suction surface of an adjacent aerofoil is less than the chord length (LC), and wherein the location of the maximum thickness of each aerofoil blade (LTmax) along the chord (LC)) is less than 20% of the chord length (L) from the leading edge.