Numerical investigation of the influences of ridge ice parameters on lift and drag coefficients of airfoils through design of experiments

The complexity of ice accretion shapes on aircraft brings challenges in establishing the physical correlations between the geometric parameters of ice and the aerodynamic performances of an airfoil. The present study applied a quarter-circle simplified ridge ice model and designed four parameters, including the lower ice horn, the height of the upper ice horn, the angle of the upper ice horn, and the location of the upper ice horn. Design of Experiments (DOE) was adopted to design the simulation process and analyze the obtained data. Numerical investigations were carried out to study the effects of these four design parameters on the lift coefficients ( CL) and drag coefficients ( CD) of three airfoils at various angles of attack. The results revealed that the four design parameters had influences on CL and CD in all simulation cases. The influence of the height of the upper ice horn was always dominant, followed by the angle and location of the upper ice horn. The influence degrees of the lower ice horn varied with the angles of attack and airfoils. The change trends of CL and CD were opposite while changing the value of any parameter in most simulation cases. In addition, the leading-edge radii of these three airfoils, as well as the shapes of the upper and lower surfaces, could alter the influences of design parameters on CL and CD.