Spatiotemporal asymmetric cavity dynamics during oblique water entry

Le résumé fourni par la source

Cavity dynamics during water entry dictate the energy transfer and fluid–structure interactions that govern projectile stability. While oblique water entry induces pronounced spatiotemporal asymmetry in cavity expansion and contraction—differentiating it from vertical entry—the quantitative scaling laws and underlying physical mechanisms of this asymmetric behavior remain elusive. In this study, the asymmetric cavity evolution during oblique water entry is systematically investigated based on a coupled theoretical and numerical framework. A revised analytical model integrating velocity decay effects into the traditional constant-velocity framework is proposed, which substantially enhances the prediction accuracy of actual cavity boundaries. Validated multiphase flow simulations subsequently reveal substantial spatiotemporal asymmetries: the maximum radius and expansion duration of the upper cavity boundary exceed those of the lower boundary by up to 99% and 163%, respectively. Flow-field analysis demonstrates that this asymmetry is driven by a highly non-uniform pressure distribution. Specifically, the upper cavity boundary experiences a weaker adverse pressure gradient compared to the lower boundary, thereby demanding less work for expansion. This dynamic pressure imbalance enables greater radial growth and prolonged expansion on the upper side, dictating the asymmetric morphology. These findings provide a crucial theoretical foundation for evaluating hydrodynamic loads and trajectory stability in complex water-entry scenarios.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.