Focus on Challenges in SLD Regime: Reemitted Droplets Models
To be published on June 10, 2019 by SAE International in United States
A lot of studies have been carried out over the last decades on SLD ice accretion challenges. Many of them referred to modelling SLD physics like break-up, splashing, bouncing, etc… and rely on numerous physics experiments. Different models have been developed In Europe and North-America and have been implemented in several numerical tools, widely in 2D but more and more in 3D. As these tools are intended to be used increasingly among the community, deficiencies have to be deeper investigated. This paper provides some highlights on specific needs linked to SLD impingement and ice accretion, especially for 3D high fidelity computations. The computations presented in this paper are performed with the in-house code AeTher developed by Dassault Aviation. The special feature of this code is that it uses finite element method for solving the impingement and bouncing equations. This leads to some difficulties regarding the reemitted impingement. After presenting the models implemented within the droplet trajectory/impingement (Trontin & Villedieu, 2016), basic validation will be presented with direct impingement on classical geometries as NACA0012 and NACA23012 airfoils. The main part will be dedicated to re-emission and secondary impingement. Reemission model characteristics will be unveiled and a typical application case using a three-element high lift configuration (see picture below) will be analyzed; impingement results will be compared to experiments and other computational results (Tan & Papadakis, 2006) for different droplet sizes and angle of attack. To the end, potential stakes for aircraft applications will be raised up. Regarding the results, lacks on numerical side and experimental needs will be highlighted in order to feed brainstorming for ongoing SLD projects, as EU H2020 ICE-GENESIS.