@article { author = {Fadaei, Ahmad and Noorollahi, Younes}, title = {2-D Numerical Simulation of Vertical Axis Wind Turbine for Performance Enhancement}, journal = {Journal of sustainable Energy Systems}, volume = {1}, number = {1}, pages = {1-14}, year = {2021}, publisher = {Iranian Geothermal Energy Association Metsap Research Lab.}, issn = {2980-8693}, eissn = {2980-8693}, doi = {10.22059/ses.2021.87477}, abstract = {IntroductionDue to its availability, high efficiency, and low cost, wind energy plays a critical role in the transition from energy sources to renewable sources in order to achieve sustainable development. In many villages of Iran where the required electricity does not exceed a few kilowatts and relatively good wind potential exists in different seasons of the year, the application of micro wind turbines as an off-grid source for supplying electricity to these areas can be effective in reducing greenhouse gas emissions and diminish the usage of thermal power plants. numerical and computational methods are able to evaluate the performance of wind turbines while reducing the cost of fabrication and testing required and provide the opportunity for optimizing the geometry and design of turbine with higher efficiencies.. To this end, this study has utilized the computational fluid dynamics analysis to predict and improve the performance of a high-solidity vertical axis wind turbine.Materials and methods The present study proposes a numerical simulation in Ansys 18 (commercial software), based on Computational Fluid dynamics (CFD) to predict the performance of a high-solidity, 3-blade, low-speed vertical axis wind turbine. In this regard, a two-dimensional fluid domain was generated, and a detailed meshing and a comprehensive mesh study were carried out. Various turbulence models were investigated and among them the Transition SST turbulence model showed the most acceptable results. Subsequently, other items including the boundary conditions, solver type, and time step were selected and optimized. To achieve a reliable solution to the problem and reduce the errors in the results, simulations were performed for 5 turbine rotation cycles.Discussion and conclusionsBased on the results, The minimum and maximum torque of the turbine per unit length for 4th and 5th revolutions are -15.03 Nm and 45.33 Nm and the average is 10.80 N. The power coefficient and the output power of the turbine rises as the tip speed ratio (turbine rotational speed) increases, reaches its maximum value and then decreases. In order to validate the simulation results, respective curves based on simulation and experimental data are provided and the amount of deviations are investigated. Following the model’s results, The maximum turbine power coefficient is 0.29 at a blade tip speed ratio of 1.62, while laboratory data reports these values as 0.253 and 1.58. therefore, there is a 23.40% difference between experimental and model results in the maximum power coefficient. Moreover, the peak turbine power of the model occurs at a speed of 80 rpm, which is equal to 333.1 watts. However, laboratory data shows maximum turbine power as 290.6 watts at 100 rpm, which is 23.40% lower than the simulation result. According to the results, the two-dimensional simulation approach tends to overestimate the values compared to the actual data. Among the contributing factors to this inaccuracy are using 2D simulation and ignoring the gradient of velocity and pressure in the Z-axis, not considering the turbine’s axis and blade-axis connections in the fluid’s domain, not considering the blades tip vortices and interaction of vortices with blades in the third dimension. Since Supplying the electricity to off-grid areas in form of distributed generation by using renewable resources have been considered to be one of the main components of sustainable development in the field of energy, vertical axis wind turbines proposed in this study are viable alternatives to commonly used diesel generator for areas with appropriate wind potential.  }, keywords = {distributed generation,High solidity vertical axis wind turbine,Computational Fluid Dynamics,2-D simulation}, title_fa = {شبیه ‏سازی دو‏بعدی توربین بادی محور عمودی با صلبیت بالا با هدف ارتقای عملکرد}, abstract_fa = {‌استفاده از توربین‏های بادی کوچک‌مقیاس به منظور تولید پراکندۀ برق برای مناطق دور از شبکۀ سراسری، ضمن کاستن از هزینه‏های احداث نیروگاه‏های متمرکز حرارتی و انتقال برق به این مناطق، از انتشار گاز‏های گلخانه‏ای توسط این نیروگاه‏ها جلوگیری می‏کند و دسترسی به انرژی پایدار و پاک را برای ساکنان این ‏مناطق فراهم می‌آورد. شبیه‏سازی‏های نرم‏افزاری اطلاعات جامعی را از عملکرد توربین‏های بادی پیش از ساخت و نصب آن‏ها در اختیار قرار می‌دهد و امکان بهینه‏سازی طراحی را فراهم می‏کند. به همین منظور و در پژوهش حاضر، ارائۀ روشی عددی و شبیه‏سازی مبتنی بر دینامیک سیالات محاسباتی در نرم‏افزار انسیس فلوئنت 18، به منظور پیش‏بینی عملکرد توربین ‏بادی محور عمودی با صلبیت بالا و سه‌پرۀ مستقیم و با هدف ارتقای عملکرد، مورد بررسی قرار گرفته ‏است. از این‏رو، پس از ایجاد هندسۀ دوبعدی میدان جریان، بهینه‏سازی شبکه‏بندی، اعمال شرایط‏ مرزی و تنظیمات حلگر نرم‏افزار، از مدل آشفتگی جریان گذار اس‌اس‌تی استفاده شد. بر اساس نتایج، بیشینۀ ضریب توان توربین معادل 29/0 در نسبت سرعت رأس پرۀ 62/1 است. همچنین، حداکثر توان تولیدی توربین برابر با 1/333 وات است. میانگین و حداقل میزان انحراف نتایج شبیه‏سازی و تست تونل‏ باد توربین، به‌ترتیب 22/19‌ و 25/6 درصد است که دقت قابل ‏قبولی دارد. نتایج این‏پژوهش روش شبیه‏سازی دینامیک سیالات محاسباتی دوبعدی را ابزاری قدرتمند و انعطاف‏پذیر در پیش‏بینی عملکرد و بهینه‏سازی طراحی توربین‏های محور عمودی در ابعاد مختلف معرفی می‌کند.}, keywords_fa = {تولید پراکنده ی انرژی الکتریکی,توربین بادی محور عمودی با صلبیت بالا,دینامیک سیالات محاسباتی,شبیه سازی دو بعدی}, url = {https://ses.ut.ac.ir/article_87477.html}, eprint = {https://ses.ut.ac.ir/article_87477_fcde1f1b63b2fcc8d1390af72fd6f13c.pdf} }