Coastal areas are regarded as one of the precious national resources in each country. Due to the fact that a striking percentage of the world's population are settled in coastal areas and also economically dependent on sea, a diversity of factors can threaten the peace and safety of these areas. One of the paramount ways dealing with these threats is the provision of coastal structures like seadikes. An important phenomenon pertinent to these structures is the overtopping and its related processes. Owing to costly and time-taking laboratory models and also development of novel numerical models, the necessity of numerical simulation to provide a deep perception of overtopping could be justified. In the present study, a 2D numerical model simulating wave interaction with impermeable coastal walls has been conducted by OpenFOAM software. By using defined boundary conditions and appropriate turbulence model, the results of numerical model are verified by experimental data. To ensure the accuracy of numerical model performance, the hydraulic and structural parameters affecting overtopping are investigated and the dimensionless parameters associated with wave overtopping are obtained through the usage of dimensional analysis. With the aim of investigating the effect of dimensionless parameters, the numerical models have been firstly applied. Subsequently, some formulae for overtopping layer thickness across the structural canopy, overtopping flow velocity at its beginning, and also the average overtopping discharge in the presence of the berm are presented.Comparison between the proposed relationship results and other researchers’ numerical results revealed that the numerical modeling results are reliable and the proposed relationships in estimating the overtopping layer thickness across structural crest, velocity at the beginning of structural crest and moderate overtopping discharge perform well. Finally, the capability of the numerical model to generate irregular waves in flume with and without the structures is investigated. Examination of irregular wave simulation draws the conclusion that OpenFOAM software is capable of simulating the irregular waves. Keywords: Seadike, wave overtopping, regular waves, layer thickness, overtopping velocity, numerical model, OpenFOAM.