Numerical Study of Powder Particle Flight Behavior during Gas Detonation Spraying Process

In the process of detonation spraying, the deposition state and the distribution of powder particles determine the performance of the coatings. High-performance coatings require powder particles to be sprayed onto the substrate at high velocity, in a molten state, and in a concentrated distribution. The effects of particle diameter, right loading distance(L), and stand-off distance(S) on the flight velocity, temperature, and distribution of alumina particles during the spraying process were studied in this paper, which was achieved through two-way coupling between the particle and fluid phases. The simulation results indicated that differences among the diameters of the various powder particles led to velocity and temperature stratification within particle stream during the spraying process. As the right loading distance increased, the deposition velocity and temperature of particles increased; while, the powder particles were more concentrated. And as the stand-off distance increased, the deposition velocity of powder particles increased; however, it might make the temperature of particles fell below melting point and the divergence of the stream of powder particles increased.