本研究提出用於流體動力發電的轉子葉片之新設計，其目的在維持強度的同時也降低轉子質量，而不大幅增加材料成本，並且將葉片模組化以降低系統組裝成本。主要的概念是使用外部纜繩將每一個葉片與通過轉子中軸的支撐柱上之不同位置做連接，葉片上的大部分負載力會被分為纜繩張力和結構壓縮力並施加至輪轂上，因此葉片上的彎矩和剪應力能夠大幅地被降低，葉片僅需更少的材料就能夠承受葉片上的負載力，所以可以在葉片中應用輕量結構以減輕重量。本研究中提出兩種新葉片結構設計：桁架結構和組合式箱型翼樑。以現有半徑40 公尺的葉片為例，由力學分析顯示應用新結構設計，在安全係數為2.5的狀況下，葉片總質量可以降低至現有值的10~17％。本研究使用組合式箱型翼樑結構以及外部纜繩，以模組化方式完成半徑1公尺的雙葉片轉子模型，並進行模型負載試驗，將外部負載掛至特定的葉片位置後，量取特定點的應變量，經由模擬結果與實驗數據的相互驗證下，可證實此結構設計確實能夠承受模擬的負載並達到輕量化的效果。這種新設計的潛在優勢包括能夠降低風力發電機的運輸和安裝成本，並對大型水輪機的潮汐、海流發電的發展可有相當的助益。

This research proposes and studies new designs for rotor blades used in fluid kinetic power generation with the aims of reducing rotor mass while maintaining strength without increasing material costs significantly and of modularizing blade construction to reduce system assembly costs. The key concept is to use a set of external cables attached to each blade at multiple positions, via a center post along the rotor axis, to redirect most of the loading exerted on the blades to the rotor hub through wire tension and structural compression rather than cantilever bending. Thus, bending moments and shear forces on blade can be reduced significantly. Correspondingly, much less materials are needed and lightweight structures can be applied in the blade to reduce weight. Two new constructions of blade structure were conceived and designed: a truss structure and an assembled spar box structure. Using a 40 m radius blade of the existing technology as an example, analyses by mechanics show that total mass of blades can be reduced to 10-17% of the existing value, under a safety factor of 2.5, by applying the new designs. Modularization designs were conceived. A model rotor of two 1 m model blades using the assembled spar box structure and the external force bearing cables design was built and assembled applying the modularization design. The model was subjected to loading tests and strain measurements at key positions on the assembled spar boxes confirmed the validity of the design. Potential benefits of this new design include reducing transportation and installation costs of wind turbines and easing the development of large water turbines for tidal/sea current power generation.

摘要 I
ABSTRACT II
圖目錄 VI
表目錄 IX
第一章 緒論 1
1.1 動機與目的 1
1.2 技術背景 6
1.3 輕量化基本概念 10
第二章 葉片結構設計與分析 17
2.1 外纜承風式葉片之力學分析 17
2.1.1無纜繩-葉片懸臂樑分析 17
2.1.2纜繩-葉片懸臂樑分析 18
2.1.3連續升力換算為節點升力 20
2.2傳統翼樑結構葉片設計與分析 22
2.3桁架結構葉片設計與分析 23
2.3.1桁架結構設計 23
2.3.2桁架結構受力分析 24
2.3.2.1平面基本桁架結構 24
2.3.2.2離心力估算 26
2.3.2.3有限單元法分析計算-雙支撐柱 27
2.3.2.4有限單元法分析計算-單支撐柱 31
2.4箱型翼樑結構設計與分析 34
2.4.1箱型翼樑結構設計 34
2.4.2箱型翼樑結構受力分析 36
2.4.2.1分析模型建立 36
2.4.2.2葉片受力分析 37
2.4.2.3慣性矩之討論 39
2.5桁架結構與箱型翼樑結構之比較 41
第三章 葉片模型試驗 43
3.1葉片模型設計 43
3.1.1葉片尺寸制定 43
3.1.2模組化組合式葉片與細部設計 44
3.2葉片分析模型 46
3.3葉片受力試驗 47
3.3.1實驗配置 47
3.3.2實驗結果與討論 50
第四章 結論 59
參考文獻 62
附錄 64
A-1葉片懸臂樑計算 64
A-2傳統葉片內部構造計算 75

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