Airfoil Optimization And Numerical Simulation Of Vertical Axis Wind Turbine

In correspondence with the much more serious environment management, wind energy are heavily favored today.Vertical axis wind turbine receives more and more attention for its advantages simple structure and good start-up performance. Wind profile are the key element of VAWT, airfoil are widely applied presently, however,with much emphasis laid on lift-drag ratio, energy conversion efficiency are neglected, which doesn’t meet the profile selection practice of VAWT.On the purpose of making some improvements, NACA0018 profile are set as original profile firstly,then the geometric parameters of the profile are optimized by method of genetic algorithm,finally numerical simulation is conducted to compare the aerodynamic performance,lift-drag ratio,efficiency between the original profile and the optimized profile,appropriate profile of VAWT are obtained.The assignments of this dissertation are summarized as follows:Ⅰ.By analyzing the working principle of VAWT,wind turbine’s positive torque range are obtained,then the formulation of lift-drag ratio and energy conversion efficiency are acquired by derivation and modification of momentum theorem as well as force analysis. Finally,turbulent flow equation and dynamic grid theory are introduced as theory foundation of optimization and numerical simulation;Ⅱ.The profile geometric optimization and inverse design are carried out by genetic algorithm method.Constraint conditions are set as the maximum thickness and profile section area no less than the original profile as well as the profile curve to be smooth continuous,using the profile obtained by fluent simulation optimization,the experimental profile meets the conditions best is acquired;Ⅲ.The VAWT’s three-dimensional model are built through gambit, the velocity cloud picture are acquired,the optimized profile operating characteristic are comprehended,the data of VAWT’s start -up torque and energy conversion efficiency are obtained for the best blade fix angle.Ⅳ.By processing and analysing experimental data, the practical torque coefficient and energy conversion efficiency are obtained,which verifies the rationality of simulation results and the selection of VAWT.By the combination of genetic algorithm method and numerical simulation, design period of VAWT is shortened. comprehensive impact elements are considered,and formed a set of design schemes of efficient and easily starting VAWT.