Dynamic Characteristics of an Underwater Ventilated Vehicle Exiting Water in an Environment with Scattered Ice Floes

The presence of ice floes on the water surface has a significant impact on the complex hydrodynamic process of submersible ventilated vehicles exiting the water. In this paper, we propose numerical simulations based on computational fluid dynamics to investigate the process of a ventilated vehicle exiting water in an ice-water mixture. The Schnerr-Sauer model is used to describe the cavitation, while the turbulence is solved by using the k-omega shear stress transport (SST) model. We also introduce the contact coupling method to simulate the rigid collision between the vehicle and the ice floe. We calculated and analyzed the process of the vehicle exiting the water under three conditions: ice-free conditions and in the presence of regularly shaped and irregularly shaped ice floes. The findings indicate that the ice floes contributed to the rapid fragmentation of the water plume to induce the premature collapse of the ventilated cavity and alter its form of collapse. The presence of ice floes intensified the evolution of the flow field close to the vehicle, and their flipping led to a significant volume of splashing water that could have led to the localized secondary closure of the cavity. Moreover, the collision between the vehicle and the ice floes caused pressure pulsations on the surface of the former, with a more pronounced effect observed on the head compared with the cylindrical section. While crossing the ice-water mixture, the vehicle was exposed to water jets formed by the flipping ice floes, which might have led to localized high pressure.