Experimental study of ice accretion effects on aerodynamic performance of an NACA 23012 airfoil

In this paper, the effects of icing on an NACA 23012 airfoil have been studied. Exper-iments were applied on the clean airfoil, runback ice, horn ice, and spanwise ridge ice at a Reynolds number of 0.6 ? 106 over angles of attack from ? 8? to 20?, and then results are compared. Gener-ally, it is found that ice accretion on the airfoil can contribute to formation of a flow separation bubble on the upper surface downstream from the leading edge. In addition, it is made clear that spanwise ridge ice provides the greatest negative effect on the aerodynamic performance of the airfoil. In this case, the stall angle drops about 10? and the maximum lift coefficient reduces about 50%which is hazardous for an airplane. While horn ice leads to a stall angle drop of about 4? and a maximum lift coefficient reduction to 21%, runback ice has the least effect on the flow pattern around the airfoil and the aerodynamic coefficients so as the stall angle decreases 2? and the maximum lift reduces about 8%.