| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 97 === Establishment of a reliable simulation model to execute the numerical analysis and predict the aerodynamic performance associated with an innovative vertical axis wind turbine (VAWT) is the main goal of this research. This new VAWT owns a 3-dimensional matrix of the wind blade panels which operate in 90 degree oppositional to each other and move uniformly in the same direction as the wind. Because this VAWT’s rotary direction goes with the wind, it creates the smooth revolution of the entire blade-panel matrix and the smooth transfer of wind energy to the vertical shaft.
Also, this integrated study is composed of the CFD calculation with LES scheme and the experimental field test for the performance verification. First of all, a series of low-Reynolds-number numerical simulation, ranging from 1.3×10^5 to 3.0×10^5, on the flow passing a horizontal plate is performed and compared to the 1/7-power-law solution for validating the accuracy of this LES model. Subsequently, after taking into account of the corrections caused by the surface friction and the angle-of-attack variation, this LES simulation outcome is agree well with the experimental data and presents an acceptable 21% deviation on the power coefficient from the field-test measurement under the condition of -5° angle-of-attack, 10 m/s wind speed, and TSR=0.125.
Later, a parametric study on the blade length ratio (β) and the wind velocity (V) is carried out to realize their corresponding influences on this VAWT’s aerodynamic performance. Within all the cases considered here, the best power coefficient (Cp=0.070) appears at β=0.8 for the case of TSR=0.25. Additionally, the highest torque coefficient (Ct=0.238) is found at the case of V=3m/s, TSR=0.25, and β=0.9. The high torque coefficient implies that this new VAWT owns a good starting capability even under a low wind speed. Furthermore, the detailed flow patterns and torque contribution for each blade/panel at various locations are illustrated and analyzed clearly in this work; thus this established model can be applied for the further performance improvement of this VAWT.
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