Abstract:
In this study, aerodynamic capabilities of NACA 0018 airfoil is numerically investigated by installing riblet on the suction side of airfoil. Numerical results were obtained by ANSYS Fluent using k-kl-kw transition model at Reynolds number of Re=100 000. Three different riblet airfoil configuration was performed at six different angles of attack (α=8°, 10°, 13°, 15°, 17° and 19°) and these results compared with the clean model. For M1 model the riblet was located at chord wise section of x/c=0.3 while it installed at x/c=0.7 for M2 model. For M3 model two riblets were used and they were located at both x/c=0.3 and x/c=0.7. Obtained numerical result show that the use of riblet remarkably affects the flow characteristics of airfoil. At α=8° the CL/CD value of M1 model is increased by 4.5% when compared to clean model. It is indicated that angle of attack at α=10o, lift coefficient is increased for all models with compared to clean model. Stall angle is delayed from α=13° to α=15° at M1 and M3 with compared to clean model and lift coefficient is increased about 37% because of the restriction of the laminar separation bubble and trailing edge separation.