Empirical model of flow-accelerated corrosion at elbow of carbon steel pipeline based on dimensional analysis

•FAC rate was measured by array electrode technique.•An effective empirical model was established to evaluate the FAC. Flow-accelerated corrosion (FAC) can result in continuous thinning of the wall thickness of water and steam-water transportation pipelines, thereby significantly compromising the safety of related systems. This study aims to investigate the behavior of FAC at a 90° elbow made of carbon steel using an array electrode technique and computational fluid dynamics (CFD) simulation. The electrochemical measurements demonstrate that the maximum rate of FAC is located on the outer side of the elbow at a temperature of 120 °C, with varying flow velocities. This observation aligns with the area where perforation is likely to occur at the elbow, consistent with the findings of power plant accidents. Additionally, an empirical model is developed to accurately predict the FAC rate at the 90° elbow through dimensional analysis. This model effectively characterizes the FAC behavior, with a maximum percentage error of 20 % between experimental and predicted values. The findings of this study offer valuable insights and provide a methodology for studying the distribution of FAC rate at a 90° elbow, which can greatly contribute to the reduction of FAC accidents.