Investigation of Numerical Irregular Wave Generation Using Transient Discrete Data as Boundary Conditions of Prescribed Velocity

Abstract

This work presents a two-dimensional numerical analysis of a wave channel. The goal is to investigate a methodology that uses transient velocity data as means to impose velocity boundary condition for generating numerical waves. To do so, a numerical wave channel was simulated using irregular waves. These waves were obtained using the WaveMIMO methodology, which converts sea data from a spectral model into time series of free surface elevation, and then converts this elevation into transient discrete wave velocity data. For the numerical analysis, computational fluid dynamics ANSYS Fluent software was employed, which is based on the finite volume method. The computational domain and mesh were generated using GMSH software, and the nonlinear multiphase model volume of fluid (VOF) was applied to tackle water-air interaction. In general, the results obtained through the use of discrete data as velocity boundary condition presented a good agreement with free surface elevation converted from the spectral model, and the tests performed provided further insight into the parameters which affect this methodology. Since many studies use regular waves, the proposed investigation stands out for its capacity to improve the use of realistic sea state data in numerical simulations of wave energy converters.