Numerical Analysis of Internal Waves Induced by an Oscillating Body in Two-layer Fluids

초록

When fluids are divided into two layers, waves exist on each boundary; the surface wave on free surface and the internal wave on the interface between upper and lower fluids. Two wave modes also occur: barotropic and baroclinic modes. The present work is to simulate the generated waves by an oscillating body in two-layer fluids. For the simulation, a 2D Numerical Wave Tank (NWT) technique is used in the frequency domain. A NWT is based on Boundary Element Method (BEM) with potential flows. The numerical results in the frequency domain are compared with analytic solutions. Two cases of a floating body located in the upper fluid and lower fluid are considered and both results are compared with various oscillating frequencies. The variation of amplitude ratio of surface to internal waves is also evaluated for various water densities.