Wave diffraction from a cylinder with porous upper wall and an inner column

Based on a linear model between the pressure difference of two sides of a porous wall and the fluid velocity inside it,an analysis solution has been established by the eigenfunction expansion method for wave diffraction from a cylinder with upper porous outer wall and an inner solid cloumn.Numerical experiment has been carried out to examine the effects on the wave force on the cylinder and wave height around the cylinder by porous coefficients of the outer wall,the ratio of radii of inner to outer column,and the water depth inside the cylinder.The numerical results show that the increase on the porous coefficient of outer column and the water depth inside the cylinder will reduce the wave elevation around the cylinder and the wave load on it.