Erosion has been recognized as one of the major threats for industries involving multiphase transportation pipelines. Within the last decades, effective parameters on wear pattern have been identified. As a result, the (famous) V-shaped erosion profile has been detected for the pipes' elbow section. In this study, CFD is employed to investigate the erosion mechanism on the square duct elbows. A novel erosion pattern has been observed for square ducts in comparison with the pipes. The impact of several parameters (particle and flow velocity, secondary flow, turbulent intensity, particle streamline) has been inspected as well. It has been led to the conclusion that the erosion rate of square ducts is lower than common pipes, especially when either higher flow velocities or bigger particles size are employed. (C) 2020 Elsevier B.V. All rights reserved.