Computational simulation of aircraft electrothermal de-icing using an unsteady formulation of phase change and runback water in a unified framework

Abstract

Accurately predicting de-icing processes is essential to ensure the proper sizing and design of ice protection systems in aircraft icing. A unified framework was developed to simulate an unsteady electrothermal de-icing process, using an unsteady formulation to account for phase change and runback water. Two physically-motivated concepts were newly introduced to the icing model to accurately describe the unsteady electrothermal de-icing (ice accretion/melting) process. A conjugate heat transfer method was utilized to tightly couple the ice and conduction solvers. Sub-iterations were incorporated at every time step to ensure the convergence of temperature and heat flux at the interface. The unsteady de-icing framework consists of a compressible Navier-Stokes-Fourier airflow solver, Eulerian droplet impingement solver, unsteady ice accretion/melting solver, and heat conduction solver, which can handle multilayer composite materials. All solvers were formulated based on partial differential equations and developed in a unified finite volume framework, enabling the use of a single grid system and eliminating unnecessary grid generation for the ice layer. The results showed better agreement with experimental data compared to other results. The unified solver was used to analyze the unsteady electrothermal de-icing process by investigating the ice accretion, ice melting, runback water film, and freezing of water film in unprotected areas. Runback water film due to ice melting may exceed the impingement limits and freeze in unprotected areas, leading to ice ridge formation.(c) 2022 Elsevier Masson SAS. All rights reserved.