Numerical simulation of three-dimensional ice accretion on an aircraft wing

• A permeable wall boundary condition is proposed to depict droplet impingement.
• Critical ice thickness is derived as a criterion for determining existence of overflow.
• Inner time step marching procedure immediately updates icing properties.
• Direct 3-D simulation has reflected spanwise flow effect properly.
• Effects of meterological parameters have been investigated and analyzed.

A method based on the Eulerian two-phase flow theory and the extended heat transfer model for numerically simulating three-dimensional ice accretions on an aircraft wing is presented in this paper. The governing equations for supercooled droplets in three-dimensional applications are established by considering the droplet phase as pseudo-fluid and applying the conservation laws of mass and momentum for a fixed control volume. A permeable wall boundary condition is proposed to depict the physical phenomenon of droplet impingement more properly. The droplet collection efficiency distribution is readily obtained from the solution of the three-dimensional droplet flowfield. Ice accretions can then be simulated through performing the mass and energy balances for each icing control volume. Some concepts such as critical ice thickness and inner time step as well as an iterative solution procedure for runback water motion have been proposed to facilitate the simulation for three-dimensional case. For validation purpose, multistep simulation results for the droplet impingement and ice accretion under specified icing conditions are compared with the corresponding experimental data and some previously predicted results, showing some better agreement gained for the current method. Furthermore, the effects of some meteorological parameters on ice accretion have been investigated and analyzed individually.