The effect of air content and compressibility on wave-in-deck impact pressures

Numerical simulations of an extreme wave impact on a topside deck structure were conducted to ascertain the effect of air content and its compressibility on the magnitude of the wave-indeck impact (slam) pressure. The topside deck was investigated as both a fixed structure and as a topside structure of a typical Tension Leg Platform (TLP) exposed to unidirectional regular waves. The volume of fluid model implemented in STAR-CCM+ was used to capture the free surface interface. CFD results were validated using different levels of mesh resolution against 1:125 model-scale experiments. In all simulated cases, the deck area exposed to a wave slam event was found to be in contact with a water-air mixture with a significant proportion of air, which revealed that two-phase models are necessary to accurately simulate wave-in-deck problems.