Coupled numerical simulation of electro-thermal anti-icing problems VII International Conference on Computational Methods for Coupled Problems in Science and Engineering COUPLED PROBLEMS 2017 M. Papadrakakis, E. O˜ nate and B. Schrefler (Eds) COUPLED NUMERICAL SIMULATION OF ANTI-ICING PROBLEMS Emiliano Iuliano * and Michele Ferraiuolo † * Italian Aerospace Research Center (CIRA) Fluid Mechanics Department Via Maiorise, 81043 Capua, Italy e-mail: e.iuliano@cira.it, web page: http://www.cira.it/it/corporate/chi-siamo/persone/dettaglio-persona?email=e.iuliano@cira.it † Italian Aerospace Research Center (CIRA) Thermo-structural Design Department Via Maiorise, 81043 Capua, Italy e-mail: m.ferraiuolo@cira.it - Web page: http://www.cira.it/it/corporate/chi- siamo/persone/dettaglio-persona?email=m.ferraiuolo@cira.it Key words: In-flight icing, coupled approach, FEM, CFD, ice protection system Abstract. The paper proposes a coupled methodology able to simulate and optimize the performance of an elec- trothermal anti-icing system in an integrated fashion: in fact, the classical tool chain of icing simulation (aerodynamics, water catch and impact, mass and energy surface balance) is coupled to the thermal analysis through the surface substrate and the ice thickness. In general, the substrate consists of a multi- layered composite with different properties for each layer and embedded heaters (resistors) at interfaces between layers. The current practice is to size the anti-icing system by evaluating the most critical icing conditions through ice accretion simulation, verifying that no ice is formed on the surface and, finally, estimating the required heating power. In the present approach, the ice protection simulation is not decoupled from the ice accretion simulation, but a single computational work–flow is considered. Valida- tion results obtained on benchmark test cases, drawn from NASA database, will be detailed as well as comparison with numerical results from other authors. 1 Introduction The formation of ice on aircraft components is a severe issue for in-flight safety. Liquid water droplets may exist in supercooled conditions up to -40 ◦ , remaining in an unstable state until they undergo an external disturbance, e.g. the impact with an aircraft surface. Depending on the environment and surface substrate conditions, the supercooled droplets may freeze immediately upon contact, partially stick and partially being ejected off the body (splashing, rebounding), deposit and flow along the surface (runback). In case of severe ice accretion, the aerodynamics of the aircraft surface can be severely deteriorated, leading to a decrease in lift and controllability and an increase in drag. Ice protection systems (IPS) are usually designed to prevent ice accretion (anti-icing systems) or to restore clean conditions (de-icing systems). The design of reliable ice protection systems (IPS) is critical and the effectiveness of such devices are required to be thoroughly demonstrated by strict regulations (14 CFR 25.1419 by the FAA or under CS 1050