近年來，為解決能源危機問題，各種替代能源研究正蓬勃發展。現今的替代能源以風力發電與太陽能發電為主，其中風力發電機可分為水平軸風力發電機與垂直軸風力發電機，本文使用商業套裝軟體FLUENT探討多顆直立葉片式垂直軸風機（Straight-Bladed Vertical Axis Wind Turbine, VAWT）的排列方式對其風機之效率與噪音影響。在此計算中利用SIMPLEC/QUICK之數值方法、k-ω紊流模型與分離渦流模擬法DES（Detached Eddy Simulation）在四邊形/三角形網格上求解非穩態不可壓縮納維史托克方程式（Navier-Stokes Equation），並採用聲場模型FW-H（Ffowcs Williams and Hawkings Equation）方程式計算流場中之噪音分貝值。首先為了解NACA0015風力發電機之間的流場現象，將網格均勻加密，並與相關之數值與實驗值比較以評估本數值模擬。接著以渦度梯度大小為基準進行網格加密去研究網格對於結果的影響，藉由上述的網格自動加密的方法以及數值原理，進行六顆風機在不同排列方式下，其流場與噪音之研究，繪出達到週期性之後的壓力分佈雲圖、渦度以及速度大小圖，根據結果可以得知，不同的排列方式下風機之間會有不同的交互作用，風機之間存在之交互作用，未必只有干擾的作用，只要排列方式正確，確實可以透過交互作用來增加效率。

In this recent years, variety of remewable energy are utilized to solve the problem of energy crisis. Nowadays, the main source are wind and solar radiation. About the wind power production, the wind turbines are divided to Horizontal Axis and Vertical Axis Wind turbine, In this study, the software package FLUENT is used to the power efficiency and noise of the Straighten-Blade Vertical Axis Wind Turbine arrays for different arrangments are investigatived. The SIMPLEC/QUICK method, k-ω turbulence model and Detached Eddy Simulation model were adopted to solve unsteady incompressible Navier-Stokes Equation on the quadrilateral/triangular meshes. To understand the decibel value of acoustic field the Ffowcs Willams and Hawkings equation was introduced. In this work, the flow field and acoustics field around two wind turbines with NACA0015 blade were computed. The uniform meshes are created, and the results were compared with numerical and experimental values in the related literatures. Also, the adaptive meshes based on the guide of vorticity are used to investigate the mesh effect on the solution. By using the above method adaptive meshes and numerical approach, the flow and acoustic field around six wind turbines arrays with different arrangments are studied. The contour of pressure, magnitude of velocity and vorticity are plotted at a period of rotation. Also, the values of sound pressure level are computed and ploted with respect to the frequency during at variou observation position. According to those results, the different interative flow fields are obtained from different arrangement. By the turbine array is appropriately arrayed, the power cofficient is increased, but the far field noise do not enhance.

參考文獻
[1]Iida A., Mizuno A., and Fukudome K., “Numerical Simulation of Aerodynamic Noise Radiated from Vertical Axis Wind Turbines, ”Proceedings of the 18th International Congress on Acoustics, 2004, CD-ROM.
[2]Carlos Simao F., Gerard van B., and Gijs van K., “2D CFD Simulation of Dynamic Stall on a Vertical Axis Wind Turbine: Verification and Validation with PIV Measurements, ”AIAA, 2007.
[3]Carlos Simao F., Ferard van B., Gijs van K., “Simulating Dynamic Stall in a 2D VAWT: Modeling Strategy, Verification and Validation with Particle Image Velocimetry Data, ”Journal of Physicsl, 2007.
[4]Mazharul Islam, and David T., and Amir F., “Desirable Airfoil Features for Smaller-Capacity Straight-Bladed VAWT, ”Wind Engineering, Vol.31, pp.165-196, 2007.
[5]Mazharul I., and David T., and Amir F., “Design of a Special-Purpose Airfoil for Smaller-Capacity Straight-Bladed VAWT, ” Wind Engineering, Vol.31, pp. 401-424, 2007.
[6]Bravo R., Tullis S., and Ziada S., “Performance Testing of a Small Vertical-Axis Wind Turbine, ”21st Canadian Congress of a Applied Mechanics, Ryerson University Toronto, Ontario Canada, June 3-7, 2007.
[7]Mazharul I., David T., and Amir F., “Aerodynamic Models for Darrieus Type Straight Bladed Vertical Axis Wind Turbines. ”Renewable and Sustainable Energy Reviews, 2008.
[8]Mazharul I., and Amir F., and Amir F., “Analysis of the Design Parameters Related to a Fixed-Pitch Straight-Bladed Vertical Axis Wind Turbine, ”Wind Engineering, Vol.32, pp. 491-507, 2008.
[9]Sylvain A., Thierry M., and Jean-Luc A., “Hydraulic Darrieus Turbines Efficiency for Free Fluid Flow Conditions versus Power Farms Conditions, ”Renewable Energy, Vol.33, pp.2186-2198, 2008.
[10]Amet E., MaîtreT., Pellone C., and Achard L., “2D Numerical Simulations of Blade-Vortex Interaction in a Darrieus Turbine,” ASME, Vol.131, 2009.
[11]Shengyi W., Lin M., Derek B. I.,Mohamed P., and Zhi T., “Turbulence Modelling of Deep Dynamic Stall at Low Reynolds Number, ”Proceedings of the World Congress on Engineering Vol.II, 2010.
[12]Akinari S., Yuichi M., Yuji T., and Yasushi T., “Interactive Flow Field around Two Savonius Turbines, ” Renewable Energy, Vol.36, pp.536-545, 2011
[13]Habtamu B., and Yingxue Y., “Double Multiple Stream Tube Model and Numerical Analysis of Vertical Axis Wind Turbine, ”Energy and Power Engineering, Vol.3, pp.262-270, 2011.
[14]Habtamu B., and Yingxue Y., “Effect of Camber Airfoil on Self Starting of Vertical Axis Wind Turbine, ”Journal of Environmental Science and Technology, Vol.4, pp.302-312, 2011.
[15]Alexandrina U., Houston G. W., Paul E. A., and Robert J. R., “Investigation of Self-Starting Capability of Vertical Axis Wind Turbines Using a Computational Fluid Dynamics Approach, ”Journal of Solar Energy Engineering, Vol.133, 2011.
[16]John O. D., “Potential Order-of-Magnitude Enhancement of Wind Farm Power Density via Counter-Rotating Vertical-Axis Wind Turbine Arrays, ”Journal of Renewable and Sustainable Energy, Vol.3, pp. 043104-1-043104-12, 2011.
[17]Kjellin J., Bulow F., Eriksson S., Deglaire P., Leijon M., and Bernhoff H., “Power Coefficient Measurement on a 12 kW Straight Bladed Vertical Axis Wind Turbine, ” Renewable Energy, Vol.36, pp.3050-3053, 2011.
[18]Marco Raciti C., Alessandro E., and Ernesto B., “The Darrieus Wind Turbine : Proposal for a New Performance Prediction Model Based on CFD,” Energy, Vol.36, pp.4919-4934, 2011.
[19]Huimin W., Jianliang W., Ji Y., Weibin Y., and Liang C., “Analysis on the Aerodynamic Performance of Vertical Axis Wind Turbine Subjected to the Change of Wind Velocity, ”SciVerse ScienceDirect, Vol.31, pp.213-219, 2012.
[20]Liang C., Huimin W., Jianliang W., Ji Y., and Weibin Y., “Analysis on the Influence of Rotational Speed to Aerodynamic Performance of Vertical Axis Wind Turbine, ”SciVerse ScienceDirect, Vol.31, pp.245-250, 2012.
[21]Ji Y., Jianliang W., Weibin Y., Huimin W., and Liang C., “Analysis on the Influence of Turbulence Model Changes to Aerodynamic Performance of Vertical Axis Wind Turbine.”SciVerse ScienceDirect, Vol.31, pp.274-281, 2012.
[22] Matthias K., Quinn M., and John O. D., “Energy exchange in an array of vertical-axis wind turbines. ”Journal of Turbulence, Vol. 13, No. 38, 2012, 1–13.
[23]韓尚育, ”小型垂直軸風機氣動力效率與噪音之數值研究,”成功大學碩士論文,2011.
[24]謝承翰, “垂直軸風力機扭力與功率的檢測與模擬,”成功大學碩士論文,2009.
[25]陳明揚,“多顆小型垂直軸風機流場之數值研究,”成功大學碩士論文2012.
[26]FLUENT 6.3 User’s Guide.2006.
[27]陳廷彰, “風扇噪音分析與有孔平板受風扇噪音激振的聲場分析,”中央大學碩士論文,2008.
[28]王俊傑, “抽油煙機之流場模擬與氣動噪音分析,”國立交通大學碩士論文,2008.
[29]FLUENT3.1 Tutorial Guide., “Aero-Noise Prediction of Flow Across a Circular Cylinder, ”Fluent Inc.,2002.
[30]World Wind Energy Association, “World Wind Energy Report,” WWEA, 2010.
[31]Bureau of Energy, Ministry of Economic Affairs.
http://www.moeaboe.gov.tw/
[32]Anthony L., Rogers, James F., Manwell, Sally Wright, M.S, “Wind Turbine Acoustic Noise,” Renewable Energy Research Laboratory, 2006.