Predicting Erosion-Corrosion Induced by the Interactions Between Multiphase Flow and Structure in Piping System

Erosion-corrosion failures frequently found in piping systems can lead to the leakage of pipes, or even damage of the whole system. Erosion-corrosion is a form of material degradation that involves electrochemical corrosion and mechanical wear processes encountered on the surface of metal pipes. Fluid-structure interactions have a profound influence on such erosion-corrosion phenomena. This paper is focused on the multiphase flow-induced erosion-corrosion phenomena in pipes, with multiscale analysis, to study the interactions between the flow and the protective film inside the piping system. The shear stress and the pressure of the flow in a pipe with a step were first obtained using a multiphase flow dynamic analysis. The erosion-corrosion rules of the pipes under the multiphase flow were then summarized. Using the microscale flow simulation method, the fluid-structure interaction between the flow and the protective film at the critical position was modeled. The deformation of the protective films was shown to vary with the flow velocity and the corresponding flow regime. According to the simulation results of the fluid-structure interaction, the location, rate, and extent of the erosion-corrosion on pipe surfaces can be predicted. The prediction was also proven by actual instances. Moreover, the method can be used in optimizing the design of the inner sleeves of pipes.