Numerical analysis of turbulent flow-accelerated corrosion in a 90° elbow

Corrosion is a material degradation that can be driven by several different mechanisms, among which flow-accelerated corrosion of metals is particularly detrimental for industrial piping systems. This degradation can cause pipes to rupture unexpectedly, forcing plant outages and creating personnel hazards, emphasizing the need for a thorough investigation of flow-accelerated corrosion. This is especially true in nuclear power plants, which rely on extensive pipe networks for both power generation and key safety systems. In this work, computational fluid dynamics was used to examine the impact of flow-accelerated corrosion in a right-angle elbow. Simulations using several turbulence models were validated and compared relative to experimental data available in the literature. Initial results showed that the k-omega turbulence model was best able to replicate experimental data across the range of parameters investigated, motivating its use in a wider range of applications with increasing complexity. A more detailed analysis was then made using the k-omega turbulence model. Particular attention was made to hydrodynamic characteristics, like flow acceleration, turbulent kinetic energy, and wall shear stress, as well as flow-accelerated corrosion intensity and corrosion rate under varying inlet velocities. The analysis revealed that the k-omega turbulence model provided the most accurate prediction of regions prone to flow-accelerated corrosion, closely matching experimental wall thinning profiles. The study also identified critical correlations between local turbulence intensity, wall shear stress, and flow-accelerated corrosion rate, offering improved understanding and predictive capability for flow-induced corrosion in complex piping geometries.