Sailcloth Windmill Segmented Blades for Rotational Efficiency
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Solution Overview
Problem
Conventional sail-wing windmills with loosely arranged blades suffer from low energy conversion efficiency due to wind escaping between blades, leading to reduced rotational efficiency and making them unsuitable for practical power generation.
Innovation Solution
A windmill device with a wind tunnel member and closely arranged sailcloth blades, where the sailcloth pieces are supported by spokes and a limb with controlled slack, ensuring a high cross-section blockage ratio and vertical opening area to direct wind flow energy into rotational energy, rotating in the same direction regardless of wind direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If blades are arranged closely in a sail-wing windmill, then energy conversion efficiency is improved by preventing wind escape, but rotational efficiency decreases due to increased resistance from wind catching
Solution Approach 1:
The windmill blades are segmented into multiple sailcloth pieces arranged in a specific pattern around the hub. Each sailcloth piece is positioned at different angular intervals, creating a segmented structure that allows wind to pass through gaps between adjacent pieces while still capturing sufficient wind energy to maintain rotational efficiency.
Solution Approach 2:
The invention transitions from a two-dimensional blade arrangement to a three-dimensional configuration where sailcloth pieces are arranged both radially and angularly around the hub. This multi-dimensional arrangement creates optimal gaps between pieces, allowing wind to pass through while maintaining effective wind capture surface area.
2Productivity
If blades are arranged apart in a sail-wing windmill, then rotational efficiency is maintained with lower resistance, but energy conversion efficiency decreases due to wind escaping between blades
Solution Approach 1:
Multiple sailcloth pieces are merged into a unified windmill structure around a common hub, with each piece contributing to the overall wind capture. The pieces are positioned and sized such that their combined effective area maximizes energy conversion while their arrangement maintains sufficient spacing for wind passage.
Solution Approach 2:
The invention optimizes parameters including the number of sailcloth pieces, their angular spacing, their radial positioning, and their individual surface areas. By carefully adjusting these parameters, the design achieves a balance where the total wind-catching area is maximized while maintaining adequate gaps for wind flow through the structure.
3Loss of energy
If a high cross-section blockage ratio is used to prevent wind escape, then energy conversion efficiency improves, but device complexity increases due to the wind tunnel member structure
Solution Approach 1:
The invention extracts and eliminates the complex wind tunnel member structure from the conventional design. Instead of using enclosed tunnels to guide wind flow, the sailcloth pieces themselves are arranged to naturally guide and capture wind through their strategic positioning and gaps, achieving effective wind direction control without additional structural complexity.
Solution Approach 2:
The sailcloth pieces are designed to self-organize and self-guide wind flow through their arrangement. The gaps between pieces naturally channel wind through the structure, and the flexible sailcloth material automatically adjusts to wind conditions, eliminating the need for complex mechanical guidance structures or wind tunnel members.
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 rotational efficiency by ensuring most wind passes through gaps between blades without escaping, improving energy conversion and making the windmill suitable for practical power generation applications, including wave power generation.
Implementation Method 1
If a wind flows from one end side to the other end side of the wind tunnel passage, the each sailcloth piece is swollen by the wind with its free end displaced toward the other end side of the wind tunnel passage. Wind flow energy is thereby converted into rotational energy, which rotates the windmill in one direction.
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
[Objective] To provides a windmill device for power generation, in which a rotational efficiency of the windmill is improved by having a wind pass though gaps between closely arranged blades without having the wind escape outside, and which is suitable to be incorporated in a practical power generation apparatus. [Means to achieve it] A windmill device including a wind tunnel member 10 with a wind tunnel passage 11 and a windmill 20 held rotatably inside the wind tunnel passage 11 of the wind tunnel member 10. The windmill 20 includes a hub 21 serving as a rotation center, plurality of spokes 22 extending radially therefrom, an approximately annular limb 23 connecting outer ends of the plurality of spokes 22, and plurality of sailcloth pieces 24, each sailcloth piece being approximately triangular in shape, one side of each sailcloth piece left as a free end 24a not supported by any of the spokes 22 and the limb 23. A ratio S2/S1 is 0.9 or more. S1 is a cross-sectional area of the wind tunnel passage. S2 is a wind catching area of the plurality of sailcloth pieces.