Rotary Vane Recess Geometry for Stable Torque in Wind Rotors
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Solution Overview
Problem
Rotary blades in existing rotating devices experience inefficiencies due to rotation resistance and variation in drag, particularly when fluid flows around the rear blade surface, leading to alternately generated maximum drag and torque variation.
Innovation Solution
The rotary blades feature a front blade surface with a recessed design and a rear blade surface with a smaller curve depth, along with a blade-support portion that guides fluid flow efficiently, reducing rotation resistance and torque variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If fluid flows along the front blade surface and goes around to the rear blade surface area, then the blade can generate rotation torque, but rotation resistance is generated on the following rotary blade
Solution Approach 1:
The patent extracts and removes the harmful fluid flow that goes around to the rear blade surface area. By designing the front blade surface to extend further in the rotation direction and positioning the rear blade surface appropriately, the patent prevents fluid from reaching the rear blade surface area, thereby eliminating the source of rotation resistance on following blades while maintaining the useful fluid flow for torque generation.
Solution Approach 2:
The patent converts the potentially harmful fluid flow that would cause rotation resistance into a beneficial effect by designing the blade surfaces to guide the fluid flow constructively. The extended front blade surface and positioned rear blade surface work together to channel fluid flow in a way that generates rotation torque without creating harmful wake effects on subsequent blades.
2Power
If maximum drag is generated when fluid is received by the rear blade surface, then rotation torque is maximized, but variation in drag with respect to rotational position is great
Solution Approach 1:
The patent applies preliminary action by extending the front blade surface further in the rotation direction before the fluid reaches the rear blade surface. This preliminary extension of the front surface intercepts and guides the fluid flow in advance, ensuring that fluid does not reach the rear blade surface area and creating a more stable drag profile across different rotational positions.
3Power
If the front blade surface is curved to protrude frontward and the rear blade surface is curved to be concave frontward, then lift is generated by speed difference, but the structure becomes more complex
Solution Approach 1:
The patent employs curvature principles by designing the front blade surface to protrude frontward and the rear blade surface to be concave frontward. These curved surfaces create speed differences in fluid flow that generate lift, improving rotational power while maintaining a streamlined structure that manages complexity through functional integration.
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 design enhances rotation efficiency by generating drag and lift through fluid flow differences and prevents fluid from bypassing the rear blade surface, resulting in improved performance and reduced resistance.
Implementation Method 1
lift generated by a speed difference between air flows flowing along the first and second curved surfaces of the front blade surface
Implementation Method 2
drag generated when wind is received by the rear blade surface
Implementation Method 3
The recess formed on the first curved surface can serve as a vortex generator. That is, local fluid stagnation (vortex) is generated at the recess
Data Source
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AI summary
This wind power generation device includes a plurality of rotary blades 15 around a rotation axis. Each rotary blade 15 includes a front blade surface 16 parallel to the rotation axis and curved so as to protrude frontward in a rotation direction, and a rear blade surface 17 located on the back side of the front blade surface 16, being parallel to the rotation axis, being curved so as to be concave frontward in the rotation direction, and having a smaller curve depth than the front blade surface 16. The front blade surface 16 includes a first curved surface 19 forming a part far from the rotation axis and formed frontward in the rotation direction from an outer end 21 of the rotary blade 15, and a second curved surface 20 forming a part close to the rotation axis L1 and formed rearward in the rotation direction from a crest 18 of the front blade surface 16 so as to connect to an inner end 22, a surface length thereof in a plan view being smaller than that of the first curved surface 19. The first curved surface 19 has recesses 23 at positions closer to the outer end 21 than to the crest 18 of the front blade surface 16. Thus, a rotary blade that rotates by receiving a fluid and can improve rotation efficiency, is provided.