Hydrophobic and superhydrophobic coatings are of great interest to the aerospace community as a measure to mitigate performance losses due to ice formation in flight. To numerically investigate the supercooled large droplets (SLDs) impacting such coated surfaces, a multiphase smoothed particle hydrodynamics (SPH) solver is developed by solving the Euler momentum equations for fluid dynamics, the energy equation for heat transfer and a latent heat model for phase changes. A continuum surface tension term is included in the momentum equations and a robust contact angle model that corrects the surface tension near triple-phase points is proposed to calculate the non-wetting effects of surfaces. The present solver is capable of modeling droplets impacting, spreading, retracting on and/or rebounding from hydrophobic/superhydrophobic surfaces, with heat transfer and phase change. It is first validated against the evolution of droplets on solid surfaces of various contact angles and then applied to droplets impacting hydrophobic and superhydrophobic surfaces at different temperatures. This work investigates SLD impingement and solidification on hydrophobic and superhydrophobic coatings and provides a base for the numerical experimentation of a single SLD icing behavior at in-flight speeds.

疏水和超疏水涂层作为减轻飞行中结冰造成的性能损失的一种措施引起了航空航天界的极大兴趣。为了对影响此类涂层表面的过冷大液滴 (SLD) 进行数值研究，通过求解流体动力学的欧拉动量方程、传热能量方程和相变潜热模型，开发了多相平滑粒子流体动力学 (SPH) 求解器. 动量方程中包含连续表面张力项，并提出了一种稳健的接触角模型，该模型可校正三相点附近的表面张力，以计算表面的非润湿效应。本求解器能够模拟液滴撞击、扩散、回缩和/或从疏水/超疏水表面反弹，具有传热和相变。它首先针对不同接触角的固体表面上液滴的演变进行了验证，然后应用于在不同温度下影响疏水和超疏水表面的液滴。这项工作研究了疏水性和超疏水性涂层上的 SLD 撞击和固化，并为飞行速度下单个 SLD 结冰行为的数值实验提供了基础。