Wave making characteristics of submerged vehicle in a stratified ocean

The numerical methods are used to obtain the wave making characteristics of pycnocline interface and free surface in a stratified ocean, the disturbance source is a submerged vehicle (SUBOFF). The unsteady viscous numerical method based on 3-D incompressible RANS equations, re-normalisation group theory k-ε turbulence model and volume of fluid method are used to simulate the fluid characteristics of the submerged body moving in a stratified ocean. Two ocean layers with finite depth and different densities are considered. Typical Froude numbers of flow vary between 0.05 and 2. The simulated results show that the wave making characteristics on the surface and interface contain contributions from two different modes: a surface-wave mode and an internal-wave mode. It is observed that there is a large effect of submerged body velocity on the wave systems, structures of free surface and pycnocline interface. The typical wavelength of the interface is predicted to increase with Froude number, which is in agreement with the theory.