Effects of Shock Waves on Impact Velocity of Cold Spray Particles

摘要

The modeling of the cold gas dynamics spray process is conducted. The Navier-Stokes equations are solved for the gas flow, including the k- turbulence model equations. The model is validated with experimental measurements for flows with and without shock waves. It predicts accurately the gas flow for both cases. A one-dimensional model is used to track the particles injected in the flow. It is shown that the effects of the shock wave present in front of the substrate are not negligible for small diameter particles and have a direct influence on their impact velocity. The spray stand-off distance is shown to have a direct effect on the flow structure and on the impact velocity of the particles. It is shown that the one-dimensional approach is not sufficient for the particle analysis.