Numerical modeling of hydrodynamics on an elevated residential structure from varied wave and surge conditions using OpenFOAM

Abstract

A Computational Fluid Dynamic (CFD) model study of wave and structure interactions on an elevated residential building under various air gap and surge/wave conditions was performed using the olaFlow, an open-source program using the OpenFOAM (Open-source Fields Operation And Manipulation) platform. The numerical model results, including free surface elevation, wave velocity, and vertical pressures on the underside of the elevated structure, showed a good agreement with the measured time-series data from the 1:6 scale hydraulic experiment (Duncan et al., 2021). The numerical simulations were used to extend the physical model tests by computing the vertical distribution of the pressure and resulting wave-induced horizontal forces/pressures, which were not measured in the physical model studies. The simulated results indicate that the pattern of pressure distributions at the frontal face of the elevated structure was controlled by water depth and wave -breaking types (nonbreaking, breaking, and broken waves). The wave induced-vertical force on the elevated structure strongly depends on wave height and the air gap, which is a net elevation from the still water level to the bottom of the structure, but the horizontal force shows complicated patterns due to the varied surge levels (flow depth), wave heights and air gaps. The new dimensionless parameter, alpha & PRIME;/h, comprised of the air gap, incident wave height, and flow depth, is introduced and utilized to predict the horizontal forces on the elevated structure.