## 1 Introduction
Aeroelastic deformation of the blade reduces aerodynamic load, also decreasing the rated output power and thrust [14; 15], in which the effect on the thrust is more significant [16], and a new numerical simulation method was used to predict the characteristics of the wind turbine such as deformation and output power [17]. In the study of blade aeroelastic properties, it was found that the deformation of solid wood material blades was more significant than that of epoxy resin material blades [18]. The wind turbine blade material was changed to obtain that the effect of blade material on the characteristics of the wrap-around flow field was greater than that of the tip speed ratio on it [19]. Modern wind turbine blades are generally manufactured from high-strength composite materials, and the analysis of wind turbine blades made of different composite materials reveals that carbon fiber epoxy resin with high stiffness and light weight is the most ideal material for wind turbine blade manufacturing, but considering the cost issue, glass fiber epoxy resin is more suitable [20; 21; 22]. In order to reduce the mass of composite blades, there are optimization frameworks based on discrete materials and lay-up thicknesses [23], and optimization methods based on blade structural stiffness and composite lay-ups are also proposed [24]. In terms of composite numerical simulation, the finite element model of the composite shell of the blade combined with aerodynamic analysis using two-way fluid-solid coupling verified that the composite shell model is necessary [25]. A composite method suitable for the wind turbine blade design profile and airfoil beams was proposed [26], and the fatigue damage of the composite blade was predicted [27]. Different lay-up methods will have different effects on the structural performance of the blade. Through the analysis and comparison of representative lay-up schemes with different lay-up angles, lay-up sequences, and lay-up ratios, the lay-up parameters with good performance of the blade are derived [28]. Taking the blade mass and torsional deformation minimization as the optimization objectives, the optimal design model of the blade was established by taking the composite single-layer thickness and the main beam position as the optimization design variables [29]. The coupling mechanism between the single-layer thicknesses of lay-up materials for large wind turbines is studied,and the influence law of the single-layer thicknesses of different lay-up materials of the blade on the modal frequency is revealed [30]. It was found that the increase in the number of lay-up layers in the beam cap can effectively provide high blade dynamics [31], and a blade regional thickness lay-up ratio was proposed to significantly increase the blade loading [32]. The fatigue reliability analysis method of wind turbine blades is explored, and the optimal lay-up thickness scheme to meet the blade reliability requirements is obtained, which effectively reduces the weight of the blade and lowers the cost [33]. In summary, the two-way fluid-solid coupling method is suitable for studying the structural and aerodynamic characteristics of wind turbines, and the composite blade lay-up method and structural characteristics are mainly studied in this research. The change in blade structural characteristics will bring about the change in aerodynamic characteristics; in particular, the influence of the change in the number of blade layers on the vortex and turbulence in the wake of the wind turbine is not clear. Therefore, after reading a lot of the literature, the two-way fluid-solid coupling calculation is carried out for composite blades with different lay-ups to investigate the deformation and stress-strain situation of composite blades with different lay-ups and the characteristics of wind turbine wake flow fields. Our objective is to provide reference basis for the subsequent aerodynamic and structural integration design of wind turbine blades.