การออกแบบและทดสอบใบกังหันลมแกนตั้งความเร็วลมต่ำ โดยการจำลองพลศาสตร์ของไหล

Abstract

Wind energy is one form of renewable energy, the most commonly known method to havest wind energy is using wind turbine by conversion of kinetic energy from wind to mechanical energy and finally to electrical energy with power generator. Normally, the wind turbine can be classifed into two types which are composed of the vertical-axis wind turbine (VAWT) and horizontal-axis wind turbine (HAWT). Each wind turbine type was evaluated and set up depending on weather condition, area site and energy demand. Due to mentioned conditions, design of wind turbine. Due to mentioned conditions, design of wind turbine is one major point that relatively affect to power efficiency of the turbine. Therefore, the main objectibes of this thesis are to study on effect of the various VAWT wind turbine structures on their efficiency and to reach the objectives, the design of wind turbines are simulated by the computational fluid dynamic (CFD). Finally, the validation of the simulated VAWT and the actual VAWT are comparative studied in terms of the wind speed, rotational speed, torque and power. At the beginning part of this work, the simulation work of the VAWT using the CFD program (called ANSYS® Fluent) was carried on. On this purpose, the simulation on simple wind turbine blade airfoil was run on 2D-simulation and the result showing in contour line of the wind speed was changed when it contacted with airfoil. And this simulated result was used for approval of wind blade structure to 3D-simulation. And the 3D wind turbine structures were carried on in various types many models. Finally, the wind turbine structures model 7 and 8 are the suitable types which were chosen for study in the deep detail. The study of the simulated wind turbine model 7 and 8 were comparatively presented with the same weather conditions and fixed wind speed of 5 m/s. However, due to limitation of the wind tunnel size the wind turbine model 8.1 and 8.2 were constructed in different size. The results shows that wind turbine model 7 has a highest rotational speed and highest power coefficient. Moreover, the wind turbine model 8.1 and 8.2 attach airfoil and curve blade on wind turbine model 8 can be reduced the lower cut-in speed while the increase of weight and wind contact area causes the wind turbine to reverse rotate in a long term operation. Finally, the effect of different wind turbine materials on efficiency of wind turbine model 7 was carried on. By adding a spindle pole in the wind turbine model 7 for good vertical installation, the materials use in study are acrylic and stainless steel was selected to build the wind turbine structures and the results show that at the wind speed of 4, 5, and 6 m/s of the acrylic wind turbine had high power coefficient and rotational speed compared to the stainless wind turbine. The comparison between simulation and experimental show the percentage of difference are 10-30% which can be improved.