Surface Waves Induced by a Moving Submarine Model

Abstract

A moving submarine can generate internal waves, as well as extremely small free surface waves, in a fluid with density stratification. In this study, the internal and free surface wave wakes caused by a moving submarine in two layers of constant density fluid were studied numerically using the commercial software STAR-CCM+. The realizable k−ε turbulence model was used to solve the Reynolds-averaged Navier—Stokes equation, and the volume of the fluid method was used to monitor the fluctuations of the internal interface and free surface. Different cases of a moving submarine with different cruising speeds and relative diving depths were studied. Results showed that the maximum fluctuation amplitude of the free surface increased as the speed of the submarine increased; however, the maximum fluctuation amplitude of the internal interface first decreased and then increased. When the submarine moved at the maximum cruising speed, the maximum fluctuation amplitude of the free surface decreased as the diving depth increased, while the wavelength of the free surface wave was basically the same. If the submarine moved at the minimum cruising speed, then the wave elevation in the free surface was extremely small, but the internal surface had obviously large-amplitude internal waves, and the relative diving depth had a great influence on internal waves.

Keywords

Free surface wave / Internal wave / Submarine / Density stratification / Cruising speed / Relative diving depth