Numerical modeling of non-breaking, impulsive breaking, and broken wave interaction with elevated coastal structures: Laboratory validation and inter-model comparisons

Quantitative CFD model validation and inter-model comparisons between IHFOAM and ANSYS-FLUENT were performed for pressures and forces on an elevated structure using a 1:10 physical model. Non-breaking, impulsive breaking, and broken wave conditions at the structure's location were simulated in IHFOAM and FLUENT. The calculated time series of water surface elevation and horizontal and vertical pressures and forces were compared with the measured data. We introduced the impulse of residual to quantify the variation of the force and pressure time series. Results indicated that the numerical models performed differently depending on the wave conditions, even for the same initial set up. Non-breaking wave simulations showed the best agreement with experimental data for both models, while broken wave trials showed the largest deviations. Bottom pressures and vertical forces were less sensitive to wave breaking conditions. Results indicate that future benchmarking tests for an elevated structure must consider both horizontal and vertical forces due to various wave breaking conditions. The accuracy of simulated wave shoaling and breaking processes played a key role in precisely calculating the forces and pressures on the structure, and it was difficult for the CFD models to simulate the exact wave breaking conditions as the measurements.