Numerical simulation of internal waves excited by a submarine moving in the two-layer stratified fluid

An unsteady viscous numerical method based on RANS equations together with VOF approach was used to simulate the internal and surface wave excited by a submarine moving in the two-layer fluid at different velocities. The near field internal waves and surface waves at different Froude numbers were given systemically. It was shown from the calculated result that with the increase of Froude number, the wavelength of internal waves is also increased while the internal Kelvin angle is decreased. The characteristic of the surface wave is quite different between the super-critical and sub-critical case. The internal waves excited by a moving submarine have the triple-lope pattern, which is similar to the surface ship case.