Abstract: The influence of turbulence intensity is generally not considered in the design of wind turbine airfoil, which leads to a large deviation between the aerodynamic design and the actual working condition. In order to match the airfoil design with the actual working condition, considering the uncertainty of turbulence intensity at stochastic turbulent condition, taking airfoil S809 as the research object, the influence of different turbulence intensity on the aerodynamic characteristics and pressure distribution of the airfoil S809 is analyzed, and the influence of turbulent uncertainty on the aerodynamic performance of the airfoil is quantified. An aerodynamic optimization strategy coupled with boundary layer transition prediction was proposed for high turbulence and low Reynolds number wind turbine airfoil. Based on non-intrusive probabilistic collocation method, the Transition SST model, the Latin hypercube sampling, the Kriging model and the genetic algorithm, the multi-objective optimization of airfoil was carried out. The results show that:After optimization, the airfoil turbulence adaptability is enhanced, the average lift-to-drag ratio is improved by 6.55%, and the standard deviation is reduced by 13.49% under turbulence condition TI~N(0.15,0.037 5²). The proposed method matches the airfoil design with turbulence, reducing the sensitivity of airfoil to turbulence uncertainty, which provides an important reference for the design and application of low Reynolds number airfoil and small wind turbines under stochastic turbulence conditions.

Key words: wind turbine airfoil, low Reynolds number, stochastic turbulence, robust design