Effects of carrier gas flow on particle in-flight characteristics during the plasma spray process with external injection

摘要

Three-dimensional numerical analysis was carried out on particle interactions within the DC plasma spray process. The plasma spray process was modeled as a jet issuing from the torch nozzle by the heating of the arc gas by an electric arc within the nozzle. Partially stabilized zirconia (PSZ) was injected into the jet with a N2 carrier gas. The plasma was modeled as a continuum compressible fluid with temperature dependent thermodynamic properties. Particles were modeled by the stochastic discrete particle model. Jet turbulence was modeled using the standard k-e model. The particle performance inside the plasma plume at various standoff distances is reported. The results show that the variation of carrier gas flow rate altered the particle behavior by reduction in plasma temperature and velocity. Also Particle trajectory is changed by the variation of carrier gas flow rate influencing the particle in-flight characteristics. Hence, it would be expected to influence the deposition process.