Numerical Simulation of Hydrodynamic Characteristics of Double-Revolving Bodies in Underwater Salvo

To study hydrodynamic characteristics in the underwater salvo process of double-revolving bodies, a three-dimensional underwater salvo model is built in this study based on the homogeneous multiphase flow theory, standard RNG k-ε model, Singhal cavitation model, and overlapping mesh technique. Numerical simulations of the evolution of an unsteady cavity are conducted to determine the movement attitudes of double-revolving bodies at different launching velocities. The flow structure evolution, motion characteristics, and salvo velocity during the salvo process under a typical condition are analyzed. The results show that the maximum development of the cavity is observed during the early stage of water navigation. As the revolving bodies move towards the free surface, the cavity gradually sheds from its end towards its top. The structure collapses owing to a flow interference region in the salvo process, because the evolution of the cavity in the shoulder of the double-revolving bodies is from asymmetric to symmetric, causing mass center deflection of the revolving bodies from the inside to the outside. As the salvo velocity increases, the length of the cavity increases at the outlet of the tube moment, the intersection point of the deflection of the center of mass from the inside to the outside is delayed backward, and the angle of deflection decreases.