Numerical simulation of metallic powder flow in a coaxial nozzle for the laser aided deposition process

Laser aided deposition process offers the ability to make a metal component directly from CAD drawings. Analysis of metallic powder flow in the feeding system is of particular significance to researchers in order to optimize this technique. Powder flow simulation holds a critical role in understanding flow phenomenon so as to ensure proper design and sound functionality of the coaxial nozzle. Numerical study of metallic powder flow in the coaxial nozzle for laser aided deposition is, however, barely existent. This is partially because not all of gas-atomized powders and none of water-atomised powders can be considered spheres and an accurate and economic modeling approach in describing non-spherical powder dispersion behavior can rarely be seen. To quickly simulate realistic powder flow and also meet the practical requirement for design optimization of the coaxial nozzle, a stochastic model, which considers particle shape effects, is developed. The validity of the model is demonstrated through comparison with experiment. The application of the model to the evaluation of various nozzle geometrical configurations is shown.