LEWICE3D, Version 3.63(LEW-19433-1)

LEWICE3D is a software system capable of predicting the accumulation of ice on three-dimensional aircraft surfaces given the flight and meteorological conditions representative of an icing cloud. The software utilizes input information of the airflow surrounding the body of interest and then calculates trajectories of approaching water droplets, the mass and energy transfer processes at the surface of the body, and the resulting ice mass and the shape it will take on the body. This version of the software includes coverage of the full range of icing conditions from the standard envelope encompassed by FAA CFR 14, Part 25, Appendix C, up through super-cooled large droplet (SLD) icing conditions. The computational results have been compared to an extensive database of ice shape profiles obtained from experimental measurements and the software has shown a very good ability to reproduce such profiles under most conditions of interest to the aviation community. This validation effort has made the LEWICE3D software one of the most extensively tested ice accretion prediction tools available.The LEWICE3D software is made up of several modules or processes. The first step is calculation of the flow field around the aircraft or aircraft component of interest. This calculation is performed prior to use of the LEWICE3D software and serves as input information for LEWICE3D. The results of this calculation are used to calculate the water droplet trajectories which impinge on the aircraft surface. The droplet trajectory analysis also produces the impingement limits and the local collection efficiency, which in turn are used to determine the mass of water that will impact a surface and the distribution of that water on the surface. The mass flux information is used for subsequent ice growth calculations and is also useful for ice protection system design. The final module or process predicts the ice shape by modeling the freezing process in small finite control volumes. Supercooled large droplet (SLD) modeling is incorporated through the computation of large droplet impact dynamics.