升阻力耦合Savonuis垂直風機之數值研究

Numerical Studies of a Savonuis Vertical Axis Wind Turbine with coupled Outer Lift/Inner Drag Blades

張良吉(Liang-Ji Chang)

指導教授 ： 戴 昌 賢 ； 徐 子 圭 ； 洪 辰 雄

國立屏東科技大學/工學院/車輛工程系所/碩士(2011年)

https://doi.org/10.6346/NPUST.2011.00203

摘要

本研究為模擬小型升阻力型耦合式垂直風機流場特性為主，風機結合了阻力型與升力型葉片，其中阻力型葉片形狀為半圓弧型，升力型的葉片翼型分別有NACA0018和NACA4412分佈於不同半徑。研究方法採用CFD計算流體力學有限體積法求解Navier-Stokes方程式，以不可壓縮流Coupled算則為主，結合非定常隱式二階上風法，再配合經網格獨立性測試之網格及具解析過渡流特徵之紊流模式，另結合滑動網格法。研究在不同風速下，分析新型風機在入口流與旋轉流二項之交互作用下之氣動力特性。其結果發現阻力型風機加了NACA0018和NACA4412葉片時，其效能比原本只有阻力型的狀態下之扭力輸出值可以高出3.4倍，本研究複合式風機的流場較為複雜，因為在流場的運算以Coupled法則為最佳方法。

關鍵字

有限體積法 ； 垂直軸式風機 ； 導風板 ； 功率

並列摘要

The aim of present thesis is to investigate the aerodynamic performance of a novel vertical-axis wind turbine (VAWT) with CFD method. The novel wind turbine blades system is composed of one or two outer rings of NACA blades and inner ring of semi-circular plates. The NACA series blades with high lift/drag ratio were used to generate enough torque force when the wind turbine is started. The inner portion of wind turbine is equipped with three to four pieces of curved plates which was considered to be worked at low wind speed environment. Two profiles of NACA series blades as NACA0018 and NACA4412 were settled on outer rings of turbine blades and their effect on the aerodynamic data were tested.
The unsteady flow structure around the wind turbine blades were obtained by solving the Reynolds-averaged Navier-Stokes equations in Fluent software. After testing various scheme to discrete the pressure term in momentum equation, the “Coupled” scheme is selected. The MRF scheme is applied to model the dynamic motion of multi-layers of wind blades. The power coefficient with respect to the tip velocity ratio is provided and discussed. Results indicated that the wind turbine with additioned blade of NACA0018 and NACA4412 can generate 3.4 times of power output as compared with that only equipped of curved-plates in central portion.

並列關鍵字

CFD ； Vertical-Axis Wind Turbine ； Profiled blades ； Power Coefficient

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