CFD Modeling and Method Validation of Erosion Damage using a combined Eulerian-Lagrangian Approach

Erosion due to particle laden flows has a significant impact on the operations of pipelines, gas turbines and machines in several industries. Our computational study aimed to model the effects of erosion damage of a stainless-steel sample due to impingement of sand entrained in an air-jet using CFD. This method validation was performed in STAR-CCM+ using a combined Eulerian-Lagrangian approach. An algorithm was devised to reconcile with the multiple time scales involved in the erosion process. First, the fluid phase was solved using the Eulerian approach, then particles were injected and tracked using the Lagrangian approach. Erosion of the sample walls was computed using a well-known erosion model. The time-averaged erosion was computed and the simulation was continued until statistical stationarity in the erosion field. In order to account for the stochastic nature of the particle paths due to turbulence, an ensemble average of several realizations was taken to obtain statistically meaningful results. This algorithm was repeated in a series of steps until the desired end time of the erosion study. A grid independence study was performed to determine the appropriate grid size. The method validation case was studied in terms of flow field, particle velocity vectors, surface profiles, surface contours, eroded surface evolution history and maximum depth of cut at different time intervals. Several conclusions regarding the erosion models, eroded surface profiles and future erosion modeling requirements were made.