Vibration Behavior of Pipelines Conveying Gas-Liquid Two-Phase Flow Supported on the Seabed

Pipe-soil interaction has been intensively investigated both theoretically and experimentally due to its importance in the design of seabed pipelines. In recently years, the effects of single phase, steady internal flow on the dynamic response of seabed pipelines have received increasing attention. However, the effects of transient two-phase flow on the vibration behavior of seabed pipelines have been seldom studied. In this work, a physical model for analyzing the dynamic behavior of a seabed pipeline conveying gas-liquid two-phase flow is proposed. Slug flow regime is considered as it causes most violent vibrations. An analytical model is adopted for the prediction of important flow characteristics of the gas-liquid slug flow. The dynamic behavior of pipelines is analytically and numerically investigated by using the generalized integral transform technique (GITT), by which the transverse vibration equation is transformed into a coupled system of second order differential equations in the temporal variable. Good convergence behavior of the proposed eigenfunction expansions is demonstrated for calculating the transverse displacement at various points of pipelines conveying gas-liquid slug flow. Parametric studies are performed to analyze the effect of the internal two-phase flow on the dynamic behavior of pipelines.