BECAUSE not all certification conditions can be ice tunnel tested, ight tested, tank tested, or encounteredin natural icing testing, only analytical methods make it possible to explore, safely, the entire icing envelope. The icing community traditionally used analytical methods to calculate impingement limits and predict ice shapes to be attached to aircraft for ight testing. Such methods are based on either two-dimensional or quasi-three-dimensional inviscid panel (incompressible potential1) ow codes to compute the air ow solution, on Lagrangian tracking techniques for droplet impingement calculations, and on a one-dimensional mass and heat transfer balance at the surface to predict ice shapes. Computational uid dynamics (CFD) technologies can overcome some of the limitations of these analytical approaches and open the way to couple aerodynamics and icing to assess the stability and control of iced aircraft or to build CFD databases for in-ight icing. The approach suggested here views icing accretion simulation as the solution of 1) the compressible turbulent Navier–Stokes