Eulerian and lagrangian ice-crystal trajectory simulations in a generic turbofan compressor

This study provides a comparison between an Eulerian and a Lagrangian approach for simulation of ice-crystal trajectories and impact in a generic turbofan compressor. The enginelike geometry consists of a one-and-a-half stage (stator-rotor-stator) compressor, in which the computed airflow is steady and inviscid. Both methods apply the same models to evaluate ice-crystal dynamics, mass and heat transfer, and phase change along ice-crystal trajectories. The impingement of the crystals on the blade surfaces is modeled assuming full deposition for comparison and validation purposes. Moreover, the effect of ice-crystal diameter and sphericity variations on impinging mass flux and particle melting ratio is briefly assessed. Then, a more realistic wall interaction model predicts rebound, shattering, or deposition as a function of impact parameters that is applied. When the full deposition model is activated, an excellent agreement is observed between the Eulerian and Lagrangian approaches for the impinging mass-flux profiles on each blade, while moderate differences appear for the melting curves. However, significant differences appear between both approaches when using the more realistic wall interaction model. The analysis of these results highlights the classic limitations of standard Eulerian and Lagrangian methods for this type of applications.