Wave-Structure Interaction (WSI) Analysis for Dam Break with Dike using SPH and ALE Methods

Rahmati-Alaei, Ahmad; Rokhy, Hamid

doi:10.22059/ceij.2025.383343.2167

Wave-Structure Interaction (WSI) Analysis for Dam Break with Dike using SPH and ALE Methods

Articles in Press

Authors

Ahmad Rahmati-Alaei ¹
Hamid Rokhy ²

¹ Assistant Professor, Department of Mechanical Engineering, National University of Skills (NUS), Tehran, Iran

² Amir Kabir University of Technology, Department of Aerospace Engineering, Tehran, Iran

10.22059/ceij.2025.383343.2167

Abstract

Dams break when their gates are suddenly removed, allowing fluid to flow instantly and causing deaths and massive damage. In addition, tsunamis can damage coastal structures. This research employs smoothed particle hydrodynamics (SPH) and arbitrary Lagrangian-Eulerian (ALE) formulations to address wave–structure interaction (WSI) problems. This study employs a weakly compressible equation of state (EOS), specifically the Murnaghan EOS, to reduce fluid compressibility and impose acceptable numerical timestep constraints using LS-DYNA. The numerical results for wave forces on the obstacle are accurately validated against experimental data. The SPH method demonstrates better agreement with experimental results compared to the ALE method. A mesh sensitivity analysis is conducted for both methods, and appropriate element sizes and particle numbers are selected for the SPH and ALE methods, respectively. The study investigates how dike height and obstacle distance impact fluid wave reduction. Comparing the H5D15 model (Fmax = 13.4 N) and H10D45 model (Fmax = 7.5 N) shows that increasing dike height is more effective than reducing the barrier distance. Longitudinal expansion decreases fluid force by 28% (to 9.8 N), while transverse expansion reduces it by 33% (from 13.6 N to 9.2 N), with transverse variations being more effective in lowering hydrodynamic wave forces.

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