Asymptotic modeling of flexible tube filled with a newtonian fluid: Application of oil flow through a riser

Abstract

The riser flexibility has yielded several advantages that have widely been used in the offshore oil and gas industry. This request has attracted many challenges to assess the dynamic riser swelling and stiffness in order to predict an eventual fatigue failure or dissection due to fluid-tube interaction. The present study provides a recent asymptotic modeling aiming at understanding the effects of the oil flow response over the dynamic behavior for a tube. The fluid is considered to be newtonian and incompressible and moves along an elastic and isotropic riser wall. The unsteady fluid flow will be analyzed following the asymptotic approach using a large Reynolds number and a small aspect ratio. Moreover, according to the small axisymmetric elastic deformation, the mathematical model of the wall equilibrium is developed on the basis of the thin shell theory where asymptotic expansion is applied. The proposed approach and its results match many numerical and experimental research works. Keywords: Asymptotic, Modeling, Flexible, Tube, Newtonian, Fluid