Numerical prediction of solid particle erosion in angle-cutting elbows with gas-solid flow

Angle-cutting elbows (ACEs) are important components of pipelines for fluid diversion and distribution. Severe erosion may occur on the internal walls of ACEs used to transport solid-gas/liquid flow. Erosion may cause pipeline failures. Therefore, the ACE erosion is a fundamental problem. However, the literature on the erosion characteristics and structural optimization of ACEs is rarely reported. This study conducts a numerical prediction of solid particle erosion in ACEs with gas-solid flow. Simulation models based on the two-way coupled Eulerian-Lagrangian approach and the E/CRC model are combined with particle-wall rebound models and a user defined function in the dispersed phase model. Simulation results are verified through a comparison with previously reported experimental results. The findings show that serious erosion occurs in the downstream part of the concave wall of ACE, whereas only slight erosion occurs on the convex wall of ACE. Therefore, anti-erosion measures should be adopted for the concave wall of ACEs. In addition, structural optimization of ACEs for erosion reduction is conducted. The optimal cutting angle is 40 degrees > 50 degrees, and the optimal non-dimensional cutting length is <1.05. The influence of fluid parameters on erosion characteristics is also determined. The erosion rate on the concave wall increases linearly with particle diameter and exponentially with inlet velocity.