As important phenomena in plasma spray, the plasma jet perturbation by the carrier gas flow and particles loading, and their effects on particle behavior are investigated. A three-dimensional computational model was developed to describe the plasma jet coupled with the orthogonal injection of carrier gas and particles. This model considered in-flight particle physical phenomena such as accelerating, heating, melting, and evaporation. The effects of carrier gas flow rates on the characteristics of plasma jet and particle spray pattern are simulated. The simulation results compare well with experimental data, for two common particle materials, NiCrAlY and ZrO2. (C) 2004 Elsevier Ltd. All rights reserved.