Research On Blade Airfoil Of H Type Vertical Axis Wind Turbine In Low Wind Speed

With the worse condition of environmental pollution, wind power has become one of the key renewable energy over the world. Modern wind turbines are mainly divided into two categories, namely horizontal axis wind turbines and vertical axis wind turbines. The main advantage of straight-bladed vertical axis wind turbine is its single moving part where no yaw mechanisms are required, untwisted blade and relative simple design of turbine configuration and structure. Because of these merits, the study of straight-bladed vertical axis wind turbine is receiving increasing attention recent years. The straight-bladed vertical axis wind turbines now experience two main tasks, self-starting of the turbine and improving the performance of airfoil, thus doing those research will benefit to the improving of turbine performance.During this thesis, XFLR program combined with Viterna-Corrignan mode was used to calculate the aerodynamic performance of NACA airfoils to analyze the Reynolds number, thickness and camber affection on the performance of airfoil. The study has shown that rising Reynolds number, proper airfoil thickness and camber will be helping to the good performance of airfoil. Using the complex method, with the objective to maximize the algebraic sum of maximum lift coefficient, maximum lift-drag ration and stall angle, a new airfoil was designed based upon NACA0015 airfoil. Aim to solve the self-starting problem, after conclusion of existing blade structure design method, a blade with flap wing was designed to resolve the self-starting problem and related mathematical mode was deduced.A test turbine has been designed and manufactured to study the influence of leading edge roughness on airfoil performance and the behavior of optimal airfoil. Moreover, the test turbine was used to verify the flap wing method and the performance of optimized airfoil. The result demonstrated that the leading edge roughness improved the self-start capability of vertical axis wind turbine, but low down its working performance. The medial surface roughness, has greater impact on turbine performance than other surfaces. The flap wing method and optimized airfoil has resolved the self-starting problem and improved the turbine performance. Further research will be benefited by these experiment results.