سعید جامعی

In this paper the influence of ground effect on the aerodynamic character of NACA 6409 were numerically studied. The simulations of the wing were performed by three dimensional Computational Fluid Dynamic (CFD). The important aerodynamic characters such as lift and drag coefficient, lift to drag ratio were determined with variation in some principle aerodynamic parameter, for instance the angle of attack and aspect ratio. The ground clearance ( h/c ) in CFD simulation was 0.1 . This simulation showed that there was enhancement on lift coefficient and reduction on drag coefficient related to incremental of aspect ratio when a aircraft flying in proximity to the ground. The K-? turbulent model was used in CFD model. Numerical results were compared with experimental data of another researcher. As a application of this CFD simulation was calculating the lift-drag coefficient and lift to drag ratio from middle wing of WIG Catamaran.