عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The combined high-order panel method and boundary layer theory applied for the calculation of the aerodynamic characteristicsof 2D airfoils moving above the free surface. The body is divided into 2nd order panels, which are approximated by the quadratic Bezier curve form. Each panel is associated with a vortex distribution of unknown strength which varies linearly.The collocation approach was employed to satisfy the Neumann boundary condition. The flow past a lifting body cannot be uniquely determined unless some additional condition (i.e. Kutta Condition) is specified. In addition, the free surface is modeled by point source singularity. Having solved for the unknown strengths, 2nd Green’s theorem can be used in order to find the potential at any point inside the fluid domain. This method is then extended to determine the viscous effect by utilizing the semi-empirical formula, which is implemented in different boundary layer regimes. Results show when the wing is close to the ground, the lift force increases while the drag decreases. In addition, the result shows the lowest point of the lower surface of the foil has to be located at the nearest possible position to the trailing edge.