The Effect of Macroroughness in Front of Building for Tsunami Pressure Dissipation—A Numerical Study

Abstract

Ocean surge may create a serious damage to coastal buildings. The surge may be generated due to high tide, storms or even from tsunami. The damage on buildings depends on shielding characteristics of the objects near the buildings. The shielding can be provided by placing small barrier or blocks in front of the considered building. It is difficult to estimate the loading on this building due to interference between waves and barrier. Wave pressure on building is numerically evaluated for the presence of macroroughness elements (small obstructions) placed in tandem arrangement in front of building. Computational Fluid Dynamics (CFD) technique is adopted for the simulation of tsunami-like solitary wave impact on macroroughness and building. Realizable k-e turbulence model is applied for turbulence modelling. Volume of Fluid (VOF) method is adopted to track the free surface movement of the flow. Wave is generated with the help of sudden discharge control at the inlet of an open channel. Wave characteristics are validated with the reported experimental results. Two types of wave height are considered in the study to evaluate the dependence between wave height and pressure on building. The results reveal that for wave height less than the building height, the placement of macroroughness is quite effective but if the wave height is more than the building height, the wave pressure reduction is not so significant.