Confrontation Between Smoothed Particle Hydrodynamics and Unsteady Reynolds-averaged Navier–Stokes Methods for a Sinking Rigid Body

Abstract

In this article, we present detailed numerical results concerning the hydrodynamic behavior of two distinct rigid bodies; a cylinder and a wedge; interacting with a free water surface. To analyze the temporal evolution of the free surface and the resulting motion of the rigid bodies, including their vertical displacements, two numerical techniques are employed: the Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) method and the Unsteady Reynolds-Averaged Navier–Stokes (URANS) approach with the Volume of Fluid (VOF) technique. Both approaches are used to predict key physical quantities such as the vertical motion and velocity of the rigid bodies, as well as the pressure distribution within the fluid domain. The results highlight the strengths and limitations of each method, showing that WCSPH excels in capturing free surface dynamics, while URANS provides more accurate pressure predictions, using measured data for validation. The findings offer valuable insights into the appropriate method selection for marine and coastal engineering applications.