Analysis of Eulerian Methods for Droplet Collection Efficiency on Two-Dimensional Surfaces Under Aircraft Icing Conditions

The calculation of droplet collection efficiency is a critical procedure in numerical simulations of aircraft ice accretion and anti-/de-icing processes, in which the Eulerian framework is predominantly employed, especially on complex surfaces. Based on the droplet streamlines obtained from the conventional Eulerian method, a new calculation method is established for droplet collection efficiency on 2D aircraft surfaces, and then a comparative analysis with the conventional approach was conducted. The results indicate that, in the absence of the droplet flow convergence effect in upstream regions, the collection efficiency calculated by the streamline-based Eulerian method aligns well with that derived from the conventional Eulerian method, and both show good agreement with numerical data from the literature, which demonstrates the feasibility and effectiveness of the streamline-based Eulerian method. When droplet concentration occurs, discrepancies in collection efficiency are observed on the corresponding downstream surfaces between the streamline-based Eulerian method and the conventional Eulerian method. Both the predicted impingement range and the total impingement mass are varied, which may be attributed to numerical diffusion. This study contributes significantly to the prediction of droplet impingement characteristics on complex surfaces and the accurate simulation of the actual aircraft icing and anti-/de-icing processes.