Effects of Chemical Kinetics on the Gas and Particle Phase Temperatures in Dual-Stage HVOF Thermal Spray Technology

The present work takes into account the impact of chemical kinetics for the combusting, highly turbulent, subsonic-supersonic, and multiphase flow in a hydrogen fueled dual stage High Velocity Oxygen-Fuel (HVOF) thermal spray coating system. The interaction between chemistry and turbulence is considered by using Eddy Dissipation Concept (EDC) combustion model. It is found that previously utilized turbulence limited combustion models, like Eddy Dissipation Model (EDM), under predict the gas and particle phase temperatures. It is quite evident that some radical recombination reactions, which are dominated in the converging–diverging nozzle, have increasing impact on the gas and particle temperatures. Moreover, the validity of some skeptical combustion reactions outside of the gun reported through EDM model in rich mixtures is studied.