Hybrid quasi molecular-continuum modeling of supercooled large droplet dynamics for in-flight icing conditions

A mesoscale model for droplet dynamics based on a quasi-molecular approach is proposed. It considers the interaction between quasi-molecules within a single liquid droplet, each quasi-molecule representing an agglomeration of a large number of actual water molecules. The goal is to improve the understanding of the dynamics of large droplets collisions over dry or wet surfaces at velocities typical of aeronautical applications. This detailed analysis will eventually be used to refine the macroscopic Eulerian description of the water impingement process by providing numerical correlations for splashing and bouncing phenomena. Approaches for extracting macroscopic quantities such as temperature and transport coefficients from the quasi-molecular method are discussed. A proper choice of the free parameter of the model that leads to accurate values of the macroscopic properties is also addressed. To model the droplet impingement process more accurately, the quasimolecular approach is then coupled with a continuum flow solver in order to include the droplet deformation effects due to the external airflow.