This paper aims to mitigate those negative effects by adding more than one flap at different distances in the circulation region. Since installing the flap on the trailing edge of airfoil increases the lift coefficient, with a negative effect represented by flow circulation and adverse pressure gradient around the flap. The present work carried out numerically on an airfoil NACA 0012 with two dimensional CFD simulations using the commercial code ANSYS FLUENT 19 and the shear stress transport (SST) k-ω turbulence model was used to simulate the flow structure around the airfoil. Single Gurney Flap, GF, with a height of 2 % chord ,c, Dual GF with heights of 2 % c and 1.5 % c and Triple GF heights of 2% C, 1.5% C, and 1% C are studied at a different attack angle in two cases, high Reynolds numbers and low Reynolds numbers. The results showed that GF has enhanced both the lift and the lift-to-drag ratio in a range for angles of attack. The computational results are compared with a published experimental result and showed good agreement with these experimental results. The results indicate that at high Reynolds number, multi GF improves the lift to drag ratio by up to 13.43 % at the attack angles of range 2˚, to 6˚.While the rates of improvement in the case of high Reynolds number are greater than that in the case of low Reynolds number. |
