Evaluation of Discrete Element Models for Prediction of Abrasive Mass Flow Rate in Abrasive Jet Machining Systems

The flow of abrasive particles in the pressurized feed system of an abrasive jet micro machining (AJM) apparatus was investigated both experimentally and computationally. The feasibility of predicting the abrasive mass flow rate using discrete element methods implemented in two commercial software packages, i.e. LS-DYNA and EDEM, was studied. A method to simulate applied pressure was developed, and computer codes to extract relative data during postprocessing were implemented. For a simplified system using spherical particles, the EDEM results better agreed with measured mass flow rates, while LS-DYNA software grossly underestimated the measured mass flow rate. The effect of pressure on mass flow rate was studied numerically using EDEM and the trends largely agreed with the experiments. Overall, it is possible to use discrete element methods to simulate powder flow in AJM systems, but only at an exceptionally high computational cost, and with considerable effort to extract relevant data.