Structural Analysis And Optimization Design Of H-type Vertical Axis Wind Turbine

With the rapid development of social economy,the supply of fossil energy has been unable to meet the growing demand of mankind.In recent years,in order to alleviate the pressure of energy demand,many countries have been developing sustainable clean energy,such as wind energy.In order to convert wind energy into electric energy,wind turbines have been developed,which can be divided into horizontal axis wind turbines and vertical axis wind turbines according to the different structure of wind turbines.According to the advantages of simple structure and strong applicability of vertical axis wind turbine,this topic selects small H-type vertical axis wind turbine suitable for towns and high-rise buildings in modern urban environment as the research objective.The main research contents of this project are as follows:(1)2D and 3D numerical simulation models of H-type vertical axis wind turbine were established with Gambit meshing software;The mesh independence and time independence of the 2D numerical simulation model were verified based on the fluid analysis software Fluent,ANSYS.The optimal mesh number was 605247 and the optimal time step was1.22E-03s(that is,the wind turbine rotates 1° at each step);(2)In order to improve the aerodynamic characteristics of the wind turbine,the maximum tangential force of H-shaped vertical axis wind turbine blade was taken as the objective function,and the third-order Bessel curve function was used to parameterize the blade airfoil structure.The Latin hypercube sampling method is used to sample in the decision space,and the response values of each sample point are solved by CFD simulation technology.The support vector proxy regression model is established to replace the third-order Bessel curve function for iterative calculation.Using the improved pollination algorithm coupled with the aerodynamic performance calculation method of XFOIL airfoil,the regression model was solved and the optimal solution was found to achieve the optimal design of the special airfoil for H-shaped vertical axis wind turbine blades.CFD simulation technology was used to analyze the lift coefficient of three new airfoils,the torque coefficient and power coefficient of H-type vertical axis wind turbine,and the optimized airfoil Opt-3 was the optimal airfoil.Compared with NACA2412 airfoil,the blade torque coefficient was improved during the rotation cycle of wind turbine.The maximum power coefficient of H-type vertical axis wind turbine is increased by 13.63%;(3)Based on fluid-structure coupling analysis,the maximum stress of wind turbine blade occurs at the hole where the blade is connected to the support frame.The maximum deformation displacement occurs at both ends of the blade and the reduction of deformation displacement is optimized;(4)The influence of the solid degree(number of blades,chord length of blades and radius of wind turbine)and blade installation Angle on aerodynamic performance of H-shaped vertical axis wind turbine was explored.In conclusion,when the blade installation Angle is-4°,the power coefficient of H-type vertical axis wind turbine reaches the maximum.The effect of blade installation Angle on the power coefficient of H-shaped vertical axis wind turbine is not related to the blade tip velocity ratio.As the blade installation Angle changes from negative to positive,the peak value of wind turbine torque coefficient curve decreases gradually;(5)In the design of wind turbine structure of small H-type vertical axis wind turbine suitable for urban and modern urban environment with tall buildings,the blade airfoil is optimized Opt-3,the number of blades is4,the chord length of blade airfoil is 0.47 m and the radius of wind turbine is 2.35 m.