Effect of blowing out on NACA0012 airfoil surface in order to prevent of ice accretion was studied numerically. Holes with regular pattern were generated over the leading edge of airfoil. Velocity of air injection, diameter, pitch of holes, and symmetrical angle of two rows about of cord line and arrangement of holes, diamond, and rectangle were varied. Shear-stress transport k-omega model was chosen to simulate the turbulence closure model, which makes better prediction for the case of pressure gradient over airfoils. Protective layer of air injections caused to prevent water droplets from the impact and strike to the airfoil surface. Results indicated that the diameter has the most effect on lowering of the ice accretion. In addition, pitch of the holes has the second most important role for reduction of ice weight. Reduction of 89% in the ice accretion in the presence of blowing out was achieved.
