عنوان مقاله [English]
When a flying vehicle approaches a surface of water or land, changes occur in the pattern of the fluid flow field around it. This change in flow field eliminates the direct effect on aerodynamics and control of the vehicle. This is more common when the vehicle is landing and taking off, as well as flying at low altitudes, which is called the surface effect. In this research, the phenomenon of surface effect and its effect on aerodynamic coefficients and flow pattern around NACA0012 airfoil in the static incompressible subsonic regime have been investigated numerically and experimentally. Experimental tests were performed in the incompressible subsonic wind tunnel of the Ghadr National Aerodynamics Research Center of Imam Hossein University with a cross-sectional area of 80 by 100 cm. The simulation of the phenomenon is a fixed ground with the minimum possible thickness of the boundary layer in the wind tunnel. Solve the flow field numerically based on Navier Stokes equations along with the Transition-SST viscous model. The impact of the surface effect phenomenon on the change of aerodynamic coefficients has been investigated by considering different distances from the surface in the static state. The pressure distribution on the airfoil surface is measured by an accurate pressure sensor and is due to the surface effect phenomenon at close distances to the surface. The results of the static analysis show an increase in lift force and a decrease in drag force.