Research On Aerodynamic Optimization And Array Distribution Of Blunt Trailing Edge Wind Wheels Of H-type Vertical Axis Wind Turbine

H-type vertical axis wind turbine has the advantages of good adaptability to turbulence and better development space in areas with less and unstable wind,and its applications in mini-grid systems in remote areas such as agricultural areas and islands are increasing.However,the layout of wind turbines with lower wind energy utilization in wind farm can affect the total power generation.Therefore,it is of great theoretical significance of guidance and engineering value of application to perform the analysis of aerodynamic performance and layout of H-type vertical axis wind turbines.In this paper,the geometrical shape of wind wheel with blunt trailing-edge blade is optimized,which takes the maximum wind energy utilization as the optimization objective.The far-field wake characteristics of H-type vertical axis wind turbines are studied,and the Gaussian Distributed Wake Model(GDWM)is modified.Based on the modified GDWM,a preliminary study is performed for the layout optimization of wind turbines in wind farm.The main research work and achievements are as follows:(1)The geometrical dimensions of the wind wheel are calculated based on aerodynamic design theory.By using mean camber and thickness function and formula of blunt trailing-edge modification,the parametric expression of blunt trailing-edge airfoil profile is established.The particle swarm optimization algorithm coupled with CFD software is used to optimize the geometrical shape of wind wheel with blunt trailing-edge blade.The change laws of wind energy utilization,pressure coefficient and vorticity distribution are analyzed and compared for the initial,blunt trailing-edge and sharp trailing-edge wind wheel.The results indicate that the optimized blunt trailing-edge airfoil can increase the pressure difference of blade at most azimuths,decrease the energy loss,and increase the wind energy utilization of wind wheel significantly.(2)The wake distribution laws of the H-type vertical axis wind turbine with different tip speed ratios and blade numbers are obtained.The GDWM is modified by the curve fitting method of combining multiple functions,and the modified GDWM is assessed using the wake wind speeds of FLUENT numerical calculation and prediction of the GDWM for blunt trailing-edge wind wheel.The results indicate that the modified GDWM has better reliability,improves the prediction accuracy of wake wind speeds of H-type vertical axis wind turbine.(3)The positions of wind turbines in wind farm are represented by binary string.Based on the modified GDWM,the layout of wind turbines in wind farm is optimized using particle swarm optimization algorithm.The results indicate that wind turbines are mostly distributed on both sides of wind farm along the wind,which reduces the influence of wake effect and the unit power generation cost of the wind farm.The total power generation of wind farm can satisfy the basic power demand of off-grid households,and the layout scheme can provide reference for micro-sitting of mini-grid system of small-scale vertical axis wind turbines.