Multi-Rotor Horizontal Wind Machine with Winglets
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Solution Overview
Problem
Conventional horizontal-axis wind machines have limited aerodynamic efficiency, typically not exceeding 59.6%, and struggle with low-wind operability due to energy loss from wind spilling over the leading edges and tips of the sails.
Innovation Solution
The design incorporates multiple rotors with angled sails along a conical surface and winglets at the leading and tip edges to capture wind energy that would otherwise be lost, along with an overrunning clutch mechanism for torque transmission between coaxial shafts, enhancing torque production and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single rotor is used, then the device complexity is low, but the aerodynamic efficiency cannot exceed 59.6%
Solution Approach 1:
The wind machine is divided into multiple independent rotor assemblies, each capable of capturing wind energy separately. The first rotor assembly and second rotor assembly operate independently but contribute to the same power output, thereby overcoming the 59.6% efficiency limit of single-rotor systems while maintaining manageable complexity through modular design.
Solution Approach 2:
Multiple rotor assemblies are combined to work together on a shared horizontal shaft. The power output from both rotors is merged to drive the same generator or work-performing device, effectively multiplying the energy capture capability while sharing common structural components to control overall system complexity.
2Device complexity
If sails are positioned perpendicular to the shaft, then the structure is simple, but wind energy is lost when wind slides off the leading edge
Solution Approach 1:
The sail configuration transitions from a two-dimensional perpendicular arrangement to a three-dimensional conical arrangement. Sails are angled backward along a conical surface rather than being perpendicular to the shaft, creating a tapered geometry that guides wind flow more effectively and prevents energy loss at the leading edge while maintaining structural simplicity.
Solution Approach 2:
The conical configuration of the sails introduces curved surfaces that better match the natural flow of wind. The angled backward orientation of sails along the conical surface creates smooth airflow paths that reduce turbulence and energy loss compared to flat perpendicular surfaces.
3Force
If multiple rotors are added, then torque production increases, but the device complexity increases
Solution Approach 1:
Multiple rotor assemblies are merged onto a single shared horizontal shaft system. Both the first rotor assembly and second rotor assembly connect to the same shaft, which transmits combined torque to a common power transmission system and generator. This merging approach multiplies torque output while avoiding the complexity of multiple independent drive trains.
Solution Approach 2:
The shared horizontal shaft and power transmission system serve multiple functions: they transmit power from both rotor assemblies, support the generator or work-performing device, and provide a common structural framework. This multi-functionality reduces overall system complexity despite having multiple rotors.
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 configuration improves low-wind start-up torque and overall efficiency by capturing otherwise lost wind energy and combining torque from multiple rotors, resulting in increased power generation compared to conventional single-rotor wind machines.
Implementation Method 1
Drag-type wind machines use relatively wide sails with large surface areas, which act to slow the wind striking the sails and convert a portion of the kinetic energy of the wind into rotary motion of the wind machine rotor
Data Source
AI summary
A horizontal-shaft wind machine having improved low wind speed performance and greater overall efficiency consists of multiple rotors, wherein each successive rotor is larger in diameter than the previous rotor moving from the most windward rotor to the most leeward rotor. Each rotor may be coupled to a separate concentric shaft, and all rotors may rotate in the same direction with the output shafts of each rotor coupled via an overrunning clutch to a single shaft, the output of which is used to drive the load. Winglets attached to the leading edge and tip of the rotor sails improve low wind startup torque.