New Roughness Computation Method and Geometric Accretion Model for Airfoil Icing

Abstract

This paper presents recent developments in wet and dry ice accretion simulation at AMIL (AntiIcing Materials International Laboratory), in a joint project with CIRA (Italian Aerospace Research Center). This paper introduces an analytical model to calculate the surface roughness and the remaining, runback, and shedding liquid water mass on an airfoil surface. Three analytical formulations are used to calculate the local roughness height based on the maximum height that a bead can reach before moving and the wave height on a water film. A mass balance is used to determine the remaining and runback water masses when the water state and the maximum bead height are known. The water shedding mass is determined using a simple mass model. A new method is used to build the accreted ice surface on the airfoils. It uses the bisection of the angle between adjacent panels to determine ice shape. The new roughness computation method and the geometric model generate the complex ice shapes observed experimentally and the results agree well with icing profiles obtained in wind tunnel experiments.