Numerical Simulations of Water Wave Propagation by Volume of Fluid Approach (original) (raw)

Generation and Propagation of Water Waves in a Two-Dimensional Numerical Viscous Wave Flume

Journal of Waterway, Port, Coastal, and Ocean Engineering, 2004

This study investigated the generation and propagation of water waves in a numerical viscous wave flume. The numerical scheme developed by Huang and collaborators for solving the unsteady two-dimensional Navier-Stokes equations for wavemaking problems was employed to generate different incident waves, including small-and finite-amplitude waves and solitary waves. The accuracy of the numerical results for the wave and velocity profiles was verified by comparison with the analytical solutions. The wave propagation in a numerical wave flume was also investigated. For periodic gravity waves on finite water depth, the results showed that waves with larger Ursell numbers are more stable than those with smaller Ursell numbers. The propagation of solitary waves in the channel is stable. For stable waves, the wave height attenuation caused by the energy dissipation in the wave motion was shown to be consistent with the theoretical results.

Validation of a piston type wave-maker using Numerical Wave Tank

Ocean Engineering, 2017

Commercial Computational Fluid Dynamics (CFD) code ANSYS-CFX which solves the Reynolds Averaged Navier-Stokes Equations (RANSE) is used to simulate waves in a 3D Numerical Wave Tank (NWT). The free surface is captured using Volume of Fluid (VOF) method. The numerical code to generate waves in NWT is first validated against experimental data to check the accuracy and robustness of the code. The experimental setup included a turbine and as such the initial numerical code was validated by comparing the wave height and the performance of the turbine against the experimental data. The initial numerical results show good agreement with the experimental data. Later an actual NWT is constructed to generate desired wave climate based on field measurements at a site in Fiji. The CFD results show very good agreement with field measured wave height of 1.23 m and field measured wave power of 9.81 kW/m. The CFD results were also verified with analytical solutions. The difference in the results is within 3% highlighting the validity of the CFD code which can further be extended to investigate other phenomena.

Generation and propagation of water waves in a two-dimensional numerical flume

ABSTRACT In this work the generation and propagation of water waves in a numerical wave flume is discussed in terms of performance and robustness. A general formulation for the analysis of fluid-structure interaction problems using the Particle Finite Element Method (PFEM) is employed to simulate a numerical wave channel. The generation of regular waves using three different types of wavemakers (flap, piston and wedge) is tested. Some conclusions on the performance and robustness of the numerical flume with respect to a physical one available at UPC are also presented.

A Computational Fluid Dynamics Investigation of a Numerically Simulated Wave Tank

American journal of mechanical engineering, 2020

In this paper, a two-dimensional Numerical Wave Tank (NWT) is proposed to calculate the static pressure variation along the lower wall of an experimental wave-flume. The experimental setup was a 4.72m long wave flume with a flap-type wave-maker. The experiments were carried out at various water heights of 100mm, 80mm, and 60mm, with a motor speed of 60 rpm. The numerical simulations were completed using ANSYS™ Fluent, with two sets solutions: 1) the unsteady, three-dimensional Reynolds Averaged Navier-Stokes (URANS) equations coupled with a k-e turbulence model; 2) unsteady 3-D Euler equations. In both computations, the volume of fluid (VOF) method was used to capture the free surface and a grid independence study was completed. The unsteady Euler simulations showed the best agreement to the experimental results. Several cases were run to complete validation and verification of the numerical model, and the CFD results are in good agreement with the experiment. Thus, for small two-di...

Modelling and simulation of surface water waves

Mathematics and Computers in Simulation, 2002

The evolution of waves on the surface of a layer of fluid is governed by non-linear effects from surface deformations and dispersive effects from the interaction with the interior fluid motion. Several simulation tools are described in this paper and compared with real life experiments in large tanks of a hydrodynamic laboratory. For the full surface wave equations a numerical FEM/FD program is described that solves both the interior flow and the surface evolution; apart from being very efficient, the program performs remarkably well. For theoretical analysis, simplified equations are desired. These can be obtained by modelling the interior flow to some degree of accuracy, leading to a single equation for the surface elevation. As representatives of this class, we discuss KdV-type of equations and, for wave packets, the NLS equation. We show that even this last equation describes quite well the large, non-symmetric deformations of the envelope of bi-harmonic waves when formulated as a signalling problem.

Comparison between wave generation methods for numerical simulation of bimodal seas

Water Science and Engineering, 2016

This paper describes an investigation of the generation of desired sea states in a numerical wave model. Bimodal sea states containing energetic swell components can be coastal hazards along coastlines exposed to large oceanic fetches. Investigating the effects of long-period bimodal seas requires large computational domains and increased running time to ensure the development of the desired sea state. Long computational runs can cause mass stability issues due to the Stokes drift and wave reflection, which in turn affect results through the variation of the water level. A numerical wave flume, NEWRANS, was used to investigate two wave generation methods: the wave paddle method, allowing for a smaller domain; and the internal mass source function method, providing an open boundary allowing reflected waves to leave the domain. The two wave generation methods were validated against experimental data by comparing the wave generation accuracy and the variance of mass in the model during simulations. Results show that the wave paddle method not only accurately generates the desired sea state but also provides a more stable simulation, in which mass fluctuation has less of an effect on the water depth during the long-duration simulations. As a result, it is suggested that the wave paddle method with active wave absorption is preferable to the internal wave maker option when investigating intermediate-depth long-period bimodal seas for long-duration simulations.

Solitary Wave Generation in Shallow Water Regions Using High Order Numerical Piston Paddle

38th IAHR World Congress - "Water: Connecting the World", 2019

Water waves have been studied for centuries to understand various physical phenomena related with them in the estuary and the coast. In particular, the solitary wave has been a classical research interest over the last 100 years. Meanwhile, the significant improvement of the computation power and resource has helped the numerical studies to solve the partial differential equations representing physical phenomena more precisely and accurately. One of convenctional question could be the gereation of wave numerically. Therefore, this study deals with how to generate solitary waves accurately with a high order numerical method. For comparison with the past experimental studies, a piston type wave-maker is implemented with the higher order method, and which is governed by a conservative form of nonlinear shallow water equation. Numerical experiments are performed with the base on the Boussinesq's solitary waves. The simulated results show that if the ratio of the amplitude to the water depth is large, waves with inadmissible errors are generated. These errors occur due to the violation of a hydrostatic pressure assumption, which is mainly used in shallow water equations, in the particular practical problem such as the relative large variations of the terrain or water surface level compared to the water depth. In order to avoid such errors and increase the accuracy of numerical experiments, nonhydrostatic pressure should be considered explicitly.

Numerical Simulations of Tsunami Wave Properties on Coastal Slopes using One Piston-Wavemaker Method

IOP Conference Series: Earth and Environmental Science

Most of the coastal area in the Ulee Lheue Bay of Aceh Besar was affected by a tsunami wave during the 2004 Indian Ocean Tsunami. Such area has an inclined bed floor which varies in slope. Variations of slope can affect tsunami wave properties such as tsunami arrival time, wave height and velocity. With those variations, the degree of the tsunami effects is highly unpredictable. Therefore, it is important to conduct a research to understand the effects of coastal slopes on tsunami waves propagations and wave deformation. Google SketchUp was used for designing the coastal slopes' 3 Dimensional models. For the tsunami waves, solitary waves were generated by using smoothed particle hydrodynamics numerical models through the DualSPHysics software. The computation was based on the meshless method. From the simulations, the waves' properties were obtained and were analyzed how coastal slopes affect the arrival time of tsunami waves, also for their height and velocity. Results show that the steepest coastal slope has the highest velocity, but shortest wave height and longest arrival time. Conversely, the flattest coastal slope has the lowest velocity, but highest wave height and shortest arrival time. Longer tsunami arrival times will benefit people in the evacuation process during the hazard.

Simulation of ocean waves in coastal areas using the shallow-water equation

Journal of Physics: Conference Series, 2019

This study simulates shallow water waves using the Navier-Stokes equation. This simulation uses the MatLab application, especially Quickersim with 2-dimensional output. Mesh in simulation is made using Gmsh. Research about shallow water has an essential role in studying the characteristics of ocean waves. The depth of the sea influences this characteristic. Data obtained from this simulation is in the wave height and velocity positions at any time. The limitations in the data collected are not comparable with the experimental results because there are no experimental Navier-Stokes simulations, but these simulation results have shown the phenomenon of seawater movement. In future work, the results of this study can be used to analyse its application in tsunami waves.