Boundary condition of a far-field viscous incompressible flow about an airfoil

The effects of far-field boundary conditions on numerical computations of a steady viscous incompressible flow about lifting airfoil is investigated. Uniform flow conditions in the presence of the circulating term and without it are considered for the case when they are specified on the boundary of the computational region. The flow about a 12% Zhukovsky airfoil at the Reynolds number $10^4$ and the angle of attack of $5\circ$ examplifies that there is a circulation value range when the condition of the airfoil pressure iniqueness is fulfiled. When there is no circulation, the pressure center lies on the 1/8 chord of the airfoil leading adge, while in the determined value range the pressure center location remain invariable and lies on the 1/4 chord of the airfolil leading edge. The problem closure requires a corresponding rezolution of the grid in the wake accounting for the next asymptotics term for boundary condition.