Optimization Of Savonius Wind Turbine Blades Based On Kriging Surrogate Model And Perturbed Stochastic Fractal Search Algorithm

Along with the rapid development of China’s economy,China’s electricity consumption is gradually rising,traditional energy reserves are gradually decreasing,and China has made two major decisions,"carbon neutral" and "carbon peak",to develop a green low-carbon economy.Under the multiple pressures of high electricity consumption,energy crisis and development of green low-carbon economy,the optimization of electricity production structure based on traditional energy sources is urgent,and wind power generation can be an important means to solve this problem.Wind power generation is realized by wind turbines.Savonius wind turbines,as wind turbines,can capture and utilize wind energy,but their low energy conversion efficiency restricts their further development.The blade as one of the most important components of Savonius wind turbine has a significant impact on the performance of the wind turbine,however,the existing blade design methods have problems such as too much reliance on the designer’s own experience,low degree of automation and intelligence,and poor enhancement effect.This study takes Savonius wind turbine blade as the research object and proposes a set of optimized design methods for Savonius wind turbine blade shape with the research objectives of improving the wind turbine performance and improving the deficiencies of existing research methods,and uses a new wind lens as an auxiliary device to improve it.Firstly,a two-dimensional CFD numerical simulation system is constructed by choosing a suitable meshing scheme and numerical solution scheme;secondly,parametric representation of wind turbine blade shape using the third-order Bezier curve-based blade profile characterization method proposed by our group,and some sample points in the design space are obtained as sample design solutions using the Latin hypercube sampling technique;then,the response values of the sample design solutions are obtained by the above numerical simulation system Then,the response values of the sample design solutions are obtained through the above numerical simulation system,and a highprecision Kriging surrogate model is constructed based on these sample design solutions and response values as a tool for wind turbine performance evaluation;again,the surrogate model is solved using a perturbed stochastic fractal search algorithm to obtain the design solution of the new blade,and it is verified and analyzed through the above numerical simulation system;finally,in order to further improve the flow characteristics around the new blade,reduce the moment fluctuation coefficient of the wind turbine,and improve the performance of Savonius wind turbine,three wind-lenses were designed and added around the new blade,and the optimization method combining Kriging model and perturbed stochastic fractal search algorithm was used to optimize the wind-lens with the best effect.Through the related research,this thesis successfully establishes a set of optimized design methods applicable to Savonius wind turbine blade shape,under which a new type of blade with better performance is obtained,and a variety of wind-lenses with excellent performance were designed on the basis of the new type of blade.It is found that the new blade has better performance at different blade tip speed ratios,and the new blade increases the power coefficient of Savonius wind turbine by 9.03% at blade tip speed ratio of 1;meanwhile,the flat wind-lens,curved wind-lens,flat-arc wind-lens and optimized flat-arc wind-lens greatly improve the flow characteristics around the new blades,reduce the moment fluctuation coefficient of the new blades and improve the performance of wind turbines,resulting in a 65.7%,66.2%,78.1% and 87.9% improvement in the power coefficient of the turbine at a blade tip speed ratio of 1,respectively.This study can break through the limitations of existing design methods,improve the energy capture efficiency of Savonius wind turbine,and lay the foundation for the optimized design of wind turbine blade shape and the application research of wind-lens,which has important theoretical value.