Investigation of vortex dynamics and load responses of an underwater-launched vehicle in wave conditions

Cavitation during underwater launch poses significant challenges, which are further exacerbated by wave-induced disturbances. This work establishes a numerical framework, integrating Large Eddy Simulation (LES), the Volume of Fluid (VOF) model, and the Schnerr-Sauer cavitation model, to investigate wave-phase-resolved cavity and vortex dynamics. Results indicate that wave motion triggers significant asymmetric evolution of the existing cavity and vortex structures. During the crest phase, downstream cavity thickness reaches 2-4 times that of the upstream side. Furthermore, cavitation notably inhibits vortex development, with vortex morphology varying by wave phase. Cavity collapse generates intense instantaneous loads; specifically, peak load amplitudes differ by up to 14.2 times between vehicle sides during the crest phase. These findings highlight strong phase-dependent load modulation, providing critical insights for the design and operation of underwater launch systems in dynamic marine environments.