A novel numerical method for applications of aero-icing predictions

Abstract

We present a new numerical algorithm for predictions of water droplets accumulation responsible for in-flight ice accretion. Unlike the traditional Lagrangian and Eulerian methodologies, the new approach is based on the single-phase multi-component lattice Boltzmann method (SPMC-LBM), which is a mesoscopic algorithm that focuses on the movement of air particles and water droplets in gas phase (vapour particles). The trajectory and impingement of the vapour particles is taken as approximately equivalent to that of water droplets. The ice growth process is simulated numerically by employing the classic Messinger’s model. The tree grid structure is used for local grid refinement and to improve the computational efficiency and robustness. To simulate water collection processes, we propose a novel approach for treating vapour particles at curved boundaries. Additionally, we develop a nondimensionalization method to convert physical diffusion coefficients into lattice diffusion coefficients, effectively capturing diffusion effects in multi-component mixed flows. For the heavier component in the mixed flow, a Lagrangian 9-bit interpolation scheme is employed for the supplement of the streaming process of the distribution functions. The numerical results show this novel method agrees well with experimental data, having a potential for development to allow tackling three dimensional geometries and complicated icing conditions. The adoption of a tree grid substantially enhances the mesh generation process. Notice as well it is an improvement for LBM related applications, since it is for the first time that LBM has been employed in the predictions on aero-icing problems.