Effect of fluid compressibility on the vertical vibrations of ship hulls

Abstract

This paper describes the effect of compressibility of fluid outside the vibrating ship hulls on the inertia and damping forces as the fluid-structure interaction. In this investigation 3-D finite element analysis is carried out to calculate the pressure fields around the uniform beam vibrating vertically with sinusoidal natural modes. Added mass and damping coefficients can be expressed as functions of frequency and nodal distances. It is found that the added mass coefficient may increase up to 5 % for the hull girder vibration of typical VLCC and bulk carriers if the compressibility is considered.