Numerical Reproduction of Regular and Irregular Free-Surface Waves in DualSPHysics: From Setup to Calibration

Accurate modeling of free-surface waves is crucial for simulating realistic ocean conditions and for analyzing wave-structure interactions. However, replicating the wave profile at target locations, especially for irregular or steep wave groups, remains a complex and technically demanding task. The current work focuses on the numerical reproduction of free-surface waves, both regular and irregular, using the Smoothed Particle Hydrodynamics method. This Lagrangian, meshless approach is implemented with the open-source solver DualSPHysics, widely used for free-surface flows in coastal and ocean engineering applications. After a theoretical overview of the method and its properties, a two-dimensional numerical wave tank was generated and optimized for wave generation and absorption. A parametric study was conducted to investigate the influence of key simulation parameters - such as particle spacing, smoothing length, and artificial speed of sound - on numerical stability and fidelity. To improve control over wave reproduction, an iterative calibration process was implemented. The simulated wave height and phase at a control location were compared with a theoretical target, and the input signal was adjusted accordingly until convergence was reached. The procedure was initially validated on regular waves and later extended to the reproduction of irregular waves with a predefined spectrum. The proposed approach, inspired by grid-based CFD strategies, was successfully adapted to the Lagrangian nature of SPH. The results confirm the method capability to accurately reproduce wave dynamics, making it a reliable tool for wave generation studies in free-surface flow contexts.