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Purpose This paper aims to introduce a three-dimensional smoothed particle hydrodynamics (SPH) framework for simulating supercooled large droplets (SLD) dynamics at aeronautical speeds. Design/methodology/approach To include the effects of the surrounding air, a multiphase model capable of handling high density-ratio problems is adopted. A diffusive term is incorporated to smooth the density field and avoid numerical instabilities. Additionally, a particle shifting technique is used to eliminate anisotropic particle distributions. Findings The framework is validated against low-speed droplet impingement experimental results and then applied to the droplet impingement at high speeds typical of SLD conditions. Preliminary parametric studies are conducted to investigate the post-impact splashing. It is observed that a thicker water film can decrease the crown diameter and a smaller impact angle can suppress upward and forward splashing. Originality/value A three-dimensional multiphase SPH framework for SLD dynamics at a wide range of impact speed is developed and validated. The effects of particle resolution, water film thickness and impact angle on the post-impact crown evolution are investigated.

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A numerical program based on the smoothed particle hydrodynamics (SPH) method has been developed to solve the nonlinear fluid-structure interaction problems. The numerical method simulates the breaking free-surface flows and evaluates hydrodynamic loads on structures. A kernel function was employed to interpolate the flow field and solve the Euler equations. The solid boundaries were modelled using a fixed ghost particle method. A particle shifting technique was adopted and improved to minimize the interpolation error caused by the non-uniform particle configuration on the free surface. Validation studies were carried out for three cases, including the dam-break flow impacting a vertical wall, water entry of a free-fall wedge and the sloshing flow in a rectangular container excited by roll motions. The numerical results were compared with the experimental data and other published numerical solutions.