Finite element analysis of a fluid-structure interaction in flexible pipe line

This paper describes the basic theory and computing method for transient flow of liquid in flexible pipe such as rubber tubing and arterial system. A mathematical model taking into account tube wall axial and radial motion (in which the dynamic fluid pressure causes circumferential and axial motion of the tube wall) is presented. The tube wall is assumed to be elastic material and the compressibility of the liquid is neglected. Circumferential and axial strain-stress relationships for the tube are considered. The obtained mathematical system is constituted of four non-linear hyperbolic partial differential equations describing the wave  propagation in both pipe wall and liquid flow. The fluid-structure interaction is found to be governed by Poisson’s ratio. In this steady finite element method based on Galerkin formulation is applied. Numerical results show a good similarity with those of the literature obtained by the characteristics method.Key words : Fluid-structure interaction, flexible pipe, rubber, finite element method