IGLOO3D Computations of the Ice Accretion on Swept-Wings of the SUNSET2 Database 2019-01-1935
NASA, FAA, and ONERA, as well as the Universities of Illinois, Virginia and Washington and the Boeing company are working on a research program, called SUNSET2, which aims to improve our understanding and ability to model ice accretion and the resulting aerodynamic effect on full-scale, 3D swept wings.
Among other activities, a database of ice shapes on CRM-like swept-wings was generated in NASA’s IRT wind tunnel. This paper discusses calculations of ice accretion on some cases of this database with the ONERA’s 3D ice accretion suite, called IGLOO3D. This tool will be described in the first part of the proposed paper. It is designed to couple three codes which solve the air flow (Navier-Stokes solver), the trajectories of water droplets (Eulerian or Lagrangian solver) and the ice accretion (Messinger approach), respectively. The coupling is made in a one-way manner by exchanging CGNS files. IGLOO3D is modular and makes it possible to couple any code as long as it reads and produces CGNS files.
The ice thickness predicted by IGLOO3D is compared against the experimental ice shapes and the LEWICE3D results. A key point for the ice accretion calculations is the effect of the convective transfer in the energy balance. This convective transfer is strongly influenced by roughness. Several approaches are shown in the present paper regarding the modelling of the effects of roughness. First, the baseline approach consists of employing the Makkonen integral model with a uniform equivalent sand-grain roughness height. Second, the heat transfer coefficient is inferred from Navier-Stokes computations with a model for roughness effects and uniform roughness height. Finally, the distribution of roughness properties is inferred from a dedicated ice shape of the SUNSET2 database. This distribution is employed for a last IGLOO3D computation. This approach is quite new for 3D ice accretion computations, it will be discussed thoroughly in the final paper.
Emmanuel Radenac, Helene Gaible, Herve Bezard, Philippe Reulet
ONERA / DMPE Université de Toulouse
International Conference on Icing of Aircraft, Engines, and Structures