Relative Length of Flap Effect on Airfoil Flow Field Structure

Based on symmetrical airfoil NACA0018 airfoil,using Fluent software numerical simulation method comparative study the relative length and the wing flap seam relative width of airfoil flow field structure and the influence of the resistance properties;The article selected the flap relative length are 0. 2,0. 3 and 0. 4 and slot relative width of 1. 0%,emphatically analyzed the flaps relative length effect on airfoil aerodynamic performance The numerical results show that:due to the impact of the main vortex development and change around the airfoil by flap,not only to improve the airfoil stall characteristics,but also improve the aerodynamic performance of airfoil. Flap airfoil stall Angle of attack within the scope of the study were greater than the benchmark airfoils,when the angle of attack is less than the stall angle of attack,the wing flap type of lift coefficient are less than the benchmark airfoils,drag coefficient were higher than benchmark airfoils,but the maximum lift coefficient are higher than the benchmark airfoil;as the relative length increases,flap airfoil critical angle of attack decreases,lift coefficient is close to the airfoil stall angle of attack,its value to present first increases then decreases;flap length at the same time,with the increase of relative width of the slot,the lift coefficient decreases.