Research on the influence of modified flaps on the aerodynamic characteristics of wind turbine special airfoil
The influence of flap modification on the aerodynamic characteristics of S809 airfoil for wind turbines was studied by numerical simulation method,and the principal of lift enhancement of flap was discussed.The results show that the flaps with inclined angles of 90° and 60° had a certain lifting effect at low-to-moderate angles of attack,and could increase the maximum lift coefficient by 5.66%and 3.95%,respectively.By analyzing the distribution of pressure coefficients of airfoils,it was found that the pressure of the pressure surface near the tail edge became larger,resulting in an increase in the lift coefficient.However,the modification of the flaps at big angles of attack led to a decrease in the lift coefficient.