Laboratory Investigation of Wave-in-Deck Slamming Loads Using Complementary PIV and BIV Measurements

Wave-in-deck slamming generates highly transient impact loads on coastal and offshore deck structures, while the hydrodynamic processes involving air entrapment and its effect on slamming pressures are not fully understood. In this study, regular-wave impacts on a rigid horizontal deck are experimentally investigated using complementary Particle Image Velocimetry (PIV) and Bubble Image Velocimetry (BIV) measurements to systematically examine the evolution of pressure response, flow dynamics (including velocity, vorticity, and turbulence intensity), and entrapped air-cavity dynamics throughout the impact, oscillation, and suction stages. The results show that during the impact stage, the primary pressure peak is generated by rapid upward momentum transfer beneath the deck, while its magnitude and spatial distribution are strongly influenced by the incident wave height and wave period. During the oscillation stage, repeated compression and expansion of the entrapped air cavity influence the post-impact pressure oscillations through continuous redistribution of the surrounding flow. During the suction stage, gravity-driven water withdrawal and progressive flow separation beneath the deck generate a sustained negative-pressure response. The combined pressure, PIV, and BIV measurements provide an experimental framework for characterizing the relationship between flow evolution, cavity dynamics, and pressure response during aerated wave-in-deck slamming.