Generation of Stable Linear Waves in Shallow Water in a ‎Numerical Wave Tank

Abstract

This paper aims to investigate numerically linear stable waves at low wave steepness in shallow water using ANSYS Fluent software. The authors mainly determined how, when, and where a linear wave will reach its stable state in shallow water. The finite volume method is used to solve the Navier-Stokes equations. The inflow velocity method and the Dirichlet boundary condition are used to generate a suitable linear wave. Numerical damping is used at the end of the tank to reduce the reflection of the wave. The accuracy and stability of the waves are judged under wave height variation between the CFD results and the analytical results. The test has been conducted in four different cases (Case 1, Case 2, Case 3, and Case 4). Wave evolution and particle velocity are obtained in the velocity field to understand the wave stability in the numerical wave tank. Numerical data are captured from the free surface to compare the surface profile and wave velocity. The results have revealed that the accuracy, stability, and consistency of the linear waves are in good agreement with the analytical solution. The relative error between the two results is 1.43% for Case 3. This research is a highly relevant source of information in realistic wave generation to design various practical systems such as wave energy converters, offshore marine structures, and many ocean engineering problems‎.

Keywords

• numerical wave tank
• stable wave generation
• inflow method
• linear wave
• shallow water