CFD Modeling of Corrugated Flexible Pipe

The objective of this paper is to present Computational Fluid Dynamics (CFD) modeling of fully developed turbulent flow through a flexible corrugated pipe and to investigate the pressure drop reduction potential of liners. This work also aims to establish a framework to be used in large scale numerical simulations of the offshore transfer of cryogenic fluids. A 3-D CFD approach is considered more appropriate than 2-D axisymmetric one, since the wavy corrugation profiles lead to a great deal of internal turbulent structures for high Reynolds number over Re > 10⁶. Three geometries of the bellows’ (corrugation) depth are considered to determine the potential value of a cryogenic liner, corrugation filler or geometric variations for the 16^″ pipe. The reduction in cost and complexity of developing a robust cryogenic liner or corrugation filler, plus eventual certifications, would be significant and needs to be worth the improvement (decrease) in pressure drop. We conduct a straight pipe corrugation depth study for pressure drop (deep corrugation, shallow corrugation and liner), and include suitable mesh convergence and unsteady simulations. We also attempt to validate the friction coefficient data with the empirical formulas and recent experimental tests. Operational cryogenic transfer flow rates ranging from Q = 1000 m³/h to Q = 5000 m³/h are considered.