Ventilated cavity dynamics of an axisymmetric body under the influence of a structure

Abstract

The presence of structures in the ocean complicates the navigation of an underwater axisymmetric body. This effect involves special environmental fluid dynamics, such as unsteadiness, strong nonlinearity, cavity multiphase flow, strong turbulence, and so forth. In this paper, an improved delayed detached eddy simulation method is used to investigate the ventilated cavity flow of an axisymmetric body in the ocean, with the intent of exploring differences in cavity multiphase flow characteristics in the presence and absence of a structure. The presence of the structure advances the deflation of the tail, shortening the length of the main body of the ventilated cavity by 21.1%. In addition, the interference of the structure increases the shedding of multi-scale vortices, while the cavity body and the shedding vortices appear asymmetrical. Moreover, the existence of the structure increases the violence of the pressure fluctuation of the axisymmetric body, where the pressure fluctuation directly below the structure reaches 57.6%, and the fluctuation of the distribution probability of the cavitation number also increases. It is worth noting that the existence of the structure does not change the main frequency of the ventilated cavity shedding in front of the structure.