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In this study a comparison is made between results from three Eulerian-based computational methods that predict the ice crystal trajectories and impingement on a NACA-0012 airfoil. The computational methods are being developed within CIRA (Imp2D/3D), ONERA (CEDRE/Spiree) and University of Twente (MooseMBIce). Eulerian models describing ice crystal transport are complex because physical phenomena, like drag force, heat transfer and phase change, depend on the particle's sphericity. Few correlations exist for the drag of non-spherical particles and heat transfer of these particles. The effect or non-spherical particles on the collection efficiency will be shown on a 2D airfoil.

In this study the characteristics of ice crystals on their trajectory in a single stage of a turbofan engine compressor are determined. The particle trajectories are calculated with a Lagrangian method employing a classical fourth-order Runge-Kutta time integration scheme. The air flow field is provided as input and is a steady flow field solution governed by the Euler equations. The single compressor stage is represented using a cascaded grid. The grid consists of three parts of which the first and the last part are stator parts and the centre part is a rotor. Each particle is modelled as a non-rotating rigid sphere. The remaining model does allow the exchange of heat and mass to and from the particle resulting in a mass, temperature and phase change of the particle. The phase change is based on a perfectly concentric ice core-water film model and it is assumed that the particle is at uniform temperature.

In this study, computational methods are presented that compute ice accretion on multiple-element airfoils in specified icing conditions. The “Droplerian” numerical simulation method used is based on an Eulerian method for predicting droplet trajectories and the resulting droplet catching efficiency on the surface of the configuration. Flow field and droplet catching efficiency form input for Messinger's model for ice accretion. The droplet trajectory method has been constructed such that the solution of any flow-field simulation (e.g., potential-flow, Euler equations) can be used as input for the finite-volume solution method. On an unstructured grid the spatial distribution of droplet loading and droplet velocity are obtained. From these quantities the droplet catching efficiency is derived. Of special interest in this study are the Supercooled Large Droplets (SLD). The simulation of SLD requires a specific splashing model.

In this study, a computational method is presented that computes ice accretion on airfoils in specified icing conditions. A good agreement is found with the ice shapes predicted by other computational methods. Agreement with the experimental ice shapes is fair. Also, the implementation and application of a mathematical model of a thermal anti-icing system in the ice accretion simulation code 2DFOIL-ICE is presented. The numerical code has proved to be able to calculate the main parameters of an airfoil anti-icing system, such as: solid surface temperatures (for the wetted region), runback water flow and convection heat transfer coefficient distributions along the external surface.