FLOW AROUND A VERTICAL HOLLOW CYLINDRICAL STRUCTURE IN A TWO-LAYER FLUID OF UNIFORM DEPTH

In this paper, we present a numerical study of a two-layer fluid flowing around a vertical hollow cylindrical structure. We analyze the effect of two-layer fluid in the presence of hollow cylindrical structure in the surface and internal wave modes. We consider a hollow cylinder within a two-layer fluid wherein the upper fluid is bounded by a free surface above and the lower fluid is bounded by an impermeable solid below. A matched eigenfunction expansion and separation of variables method are used to obtain the diffracted velocity potentials in the identified domains. The obtained diffracted velocity potential gives us the wave elevation at the surface and the internal wave modes. We present the wave elevations with different parameters of the device in various wave modes of motion, including surface waves and internal waves. It is observed that in the surface mode, the free surface elevation is higher than the interface elevation and the free surface and the interface elevations are in same phase whereas in the internal wave mode, the elevation at the interface is greater than that at the free surface.