Numerical investigation of erosive wear considering surface degradation using coupled CFD-DEM and a bond model

Abstract

A three-dimensional simulation model is proposed here to study the erosive wear of structure caused by solid particles, which accounts for the accumulation of surface deformation and degradation during the erosion process. Although there are numerous studies on the erosion, they have been primarily based on semi-empirical equations to predict the material loss and lack of an engineering approach to account for the surface evolution during erosion process, which is proved to be of great important. Our proposed model aims to overcome these challenges. In this approach, a conventional volume of solid object is discretized into a number of discrete spherical elements. A bond network is added to connect neighbouring particles at micro-scale, forming a cohesive structure at macro-scale. It is indeed a combination of particulate flow simulation by coupled Computational Fluid Dynamics (CFD) - Discrete Element Method (DEM) and materials modelling by DEM using a bond model. An extensive study of fluid response in both laminar and turbulent flow is conducted when the traditional continuous rigid object is replaced by a corresponding discrete deformable object composed of bonded spherical particles. The replacement of discrete object allows this model to naturally incorporate the three-way interaction of fluid, structure, and particles. The interaction between fluid and structure at macro-scale is implicitly represented by the interaction between fluid and bonded particles at micro-scale, while material properties and the micro-structure of the solid object are reproduced by properties of bond that account for deformation and fracture. Both resolved and unresolved coupling schemes result in good agreement with the traditional CFD approach.