垂直軸風力機轉子葉片變因操縱的教案設計研究

本文內容以中學生為對象，設計小型垂直軸風力機以及動手做自製環保風車風能教案，引導學生認識風力發電及風力機發電特性。首先進行轉子性特的實驗分析，以不鏽鋼製作塔架、葉片支架，並使用硬紙板、珍珠板等簡易材料製作葉片以驅動發電機，再利用瓦楞板製作簡易風洞，針對不同翼型與不同弦長的葉片進行實驗，此風力機也於健行科技大學綠能實驗室風洞進行實驗。實驗顯示風機輸出功率隨葉片翼型厚度增加而提高，但葉片弦長太長反而造成功率下降，尾流干擾其可能是主要因素。本文實驗以H型垂直軸風力機為對象，實驗結果顯示NACA0022、弦長12cm的葉片轉子，在6m/s風速下的最大Cp值約為0.19，而NACA0018、弦長10cm的最大Cp值約只有0.15。依據實驗結果所得轉子特性設計風能教案，並進行風能教育教學，讓學生發揮創意，動手做環保風車，培養學生的創造力、操作力與風力機優化的概念。最後引入難度較深的H型垂直軸風力機，提供翼型與弦長各三種供學生操縱選擇，以分組競賽方式進行，增加學生對風力發電的認知，結果顯示學生對於風力發電的認識獲得了提升。

關鍵字

小型垂直軸風力機；自製環保風車；風洞；教案

並列摘要

In this article we proposed a teaching project for junior school students to learn about the wind power and electricity generation by wind turbine with DIY homemade windmill and the design of small vertical axis wind turbines. Rotor characters are performed with experiments and analyzed in the beginning. Turbine frame made with steel and rotor blades made with simple materials such as hard papers are built up to drive a 50W generator. A simple wind tunnel was applied as well to perform experiments for different airfoils with different chord lengths. Such wind turbine also performed more experiments in the wind tunnel of UCH in higher wind speed conditions. Experiments show that the thicker airfoil has the more output power but the too long chord length will decrease the output power due to wake interference. Experiments of H-type vertical axis wind turbine show that airfoil NACA0022 with chord length 12cm has the maximum Cp value 0.19 as the wind speed is 6m/s but NACA0018 with chord length 10cm only has the maximum Cp value 0.15. We developed a teaching project for high school students to perform wind energy education based on the above results. The goal is to lead students more creative and build up their operating ability and skills on rotor optimization. The further course introduce H-type vertical axis wind turbine and guide students to learn how the output power change with the changing in airfoil and chord length. Investigation shows that students do increase their interest and understanding in wind energy topics.