Study of Turbulent Behavior and Particle Flight Characteristics Based on Different Turbulence Models During HVOF Spraying

High-velocity oxygen fuel (HVOF) thermal spraying technology has been widely used to prepare anti-corrosion and wear-resistant coatings. In this study, the compressible turbulent flow, combustion reaction, and particle flight characteristics in a JP8000 spray gun were calculated. The turbulence models of realizable k–ε, RSM, and SST k–ω were analyzed and compared. Based on the realizable k–ε model, the effects of particles for incidence velocity, incidence angle, and shape on particle flight behavior during spraying are discussed in detail. The results show that the realizable k–ε model predicts that the surface pressure effect at the particle inlet is obvious and that the local turbulence intensity is relatively high. The combustion reaction predicted by the RSM model occurs relatively slowly, is concentrated in the back part of the combustion chamber, and takes into account the accumulation of oxygen concentration. When the particle incidence angle is − 45° and the injection velocity is 10–20 m/s, the flight path is closer to the gun axis, which is conducive to particle heating and acceleration. Particle morphology has a significant effect on flight behavior, particles with low shape factor should be selected for their large size, and particles with a high shape factor should be selected for their small size.