NUMERICAL SIMULATION AND EXPERIMENTAL INVESTIGATION OF THREE-DIMENSIONAL GAS-JET TRANSPORTATION OF POWDER PARTICLES IN DIRECT MATERIAL DEPOSITION

摘要

This paper presents experimental and theoretical results of studies the DMD processes. Three dimensional physical and mathematical analysis of gas-jet transportation of powder particles has been developed. A detailed research of gas and powder stream parameters for coaxial nozzle is performed. The distribution of the 3D mass-flow and the density of powder flow are calculated and the positions of the local powder focus area in the space between the nozzle and the substrate are determined. A dedicated device has been designed and implemented in order to measure the 3D powder jet profiles of existing nozzles. A laser plane from a diode laser He-NE source is placed perpendicularly to the powder jet and creates a 2D slice of the powder flow by lighting it at a given height. Comparisons of numerical simulation results with experimental data are presented. It gives more complete understanding of the physical mechanisms of the processes.