Author(s): Debasish Dutta; Lalit Kumar; Mohammad Saud Afzal

Linked Author(s): Mohammad Saud Afzal

Keywords: CFD; Hydrodynamics; REEF3D; Combined wave current

Abstract: The flow hydrodynamics in coastal and marine environments is very complex, hence its study is important to analyze the causes of scour that leads to the failure of coastal structures. It is one of the most difficult tasks, involving the complexity of the wave-current structure interaction problem. In this regard, CFD (Computational Fluid Dynamics) is a very strong tool to compute the wave-current hydrodynamic effect on a structure. The present study focuses on the combined wave-current hydrodynamics on the circular cylinder in different arrangements (tandem, side by side, staggered). This study is done by the open-source CFD code REEF3D. The model solves the Reynolds-Averaged Naiver Stokes equation with k-ω turbulence closure to get the flow hydrodynamics and the level set method is used for capturing the free surface. The model is first validated with the experimental results, which shows a satisfactory agreement between the numerical results and experimental data. The code utilizes a staggered cartesian grid system. Also, Message Passing Interface (MPI) based parallelization is used for domain decomposition. Dirichlet and active wave absorption boundary condition is used for the generation and absorption waves in the numerical wave tank. The convection terms in the Navier-Stokes equations and the level set method are discretized with the 5th-order Weighted Essentially Non-Oscillatory scheme. The flow hydrodynamics is predicted for different wave-current and for different arrangements of circular piers.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221698

Year: 2022