Study of flow structure in erosion prone complex geometries

Abstract

Erosion is a challenge in a wide range of industries where fluid is transferred through pipes, valves and other mechanical arrangements. Wear can occur due to a variety of mechanisms but is often related to the presence of droplets or solid particles in the fluid stream. This article presents a study of flow relevant to solid particle erosion in a converging-diverging axisymmetric geometry. The purpose of the study was firstly to investigate the flow characteristics as a function of changes in geometry and compare with empirical data. Secondly, steady state, transient simulations and geometrical simplifications were compared to investigate methods of reducing computational time. Thirdly, the flow structure from each simulation was compared to identify any discrepancy in the simulated velocities in the near wall areas, where erosion is observed, in the diverging section of the geometry. The accuracy of simplified models compared to experimental data were found to be satisfactory with respect to global parameters such as pressure drop and flow coefficient. However, the comparison of steady state, transient, axisymmetric sectioning and full models identified significant discrepancy in local velocities in erosion prone areas, which would affects any erosion rate prediction significantly.