Numerical study of seaplane slamming into non-Newtonian fluid using coupled 3D SPH

In ocean environments or other settings characterised by complex task spaces and complicated multiphase flow problems, predicting the slamming behaviour and hydrodynamic performance of seaplanes becomes increasingly challenging. This study establishes a graphics processing unit-accelerated framework based on a three-dimensional smoothed particle hydrodynamics (SPH) flow model to investigate the slamming behaviour during the coupling interaction between a seaplane and a non-Newtonian fluid. Firstly, a convergence analysis and model validation were conducted to verify the accuracy and stability of the proposed 3D SPH coupling model. Subsequently, a detailed analysis of the dynamic characteristics of a seaplane slamming into a non-Newtonian fluid was carried out using SPH numerical simulations, considering different impact velocities and various constitutive models of the non-Newtonian fluid. The analysis covered motion responses, slamming load features, and free-surface evolution. Owing to the meshless nature of the SPH method, the detailed flow behaviour of the non-Newtonian fluid during the slamming process can be effectively captured. The results indicate that the rebound tendency, acceleration response, and pitch motion of the seaplane are strongly affected by the rheological parameters of the non-Newtonian fluid. In particular, high-yield-stress shear-thickening fluids may suppress complete bouncing but increase horizontal deceleration and forward-pitching tendency under high-speed impact conditions. Since the present study treats the seaplane as a rigid body, the conclusions are limited to motion response and hydrodynamic load characteristics, while structural deformation and stress failure require further coupled SPH–finite element method analysis.