A Novel Method Based on Eulerian Streamlines for Droplet Impingement Characteristic Computation Under Icing Conditions

Ice accretion alters the airfoil profile of the unmanned aerial vehicle (UAV), degrading the aerodynamic performance and potentially triggering safety incidents. The computation of droplet impingement characteristics is the primary task for ice accretion analysis and the design of anti-icing/de-icing systems for UAVs. To address the disadvantages of the conventional Eulerian method and the Lagrangian method, a streamline-based Eulerian method is established to obtain the droplet impingement characteristics. It only solves the momentum equation to derive the velocity field, eliminating the computational load of the droplet continuity equation. Droplet streamlines are generated via backward integration in the droplet velocity field, allowing impingement characteristics to be calculated. In this scheme, the droplet collection efficiency is computed without the predetermination of droplet release locations or tracking a large number of droplet trajectories. The proposed method is applied to obtain the droplet collection efficiencies in the cases of an NACA0012 airfoil, a two-dimensional (2D) cylinder, an MS (1)-0317 airfoil, and an RG-15 airfoil. The results show good agreement with the data in the literature; therefore, the feasibility and effectiveness of this streamline-based Eulerian method are confirmed. This work can provide a reference for ice accretion analysis and anti-icing/de-icing system design for UAVs.