G050044 Numerical simulation on the influence of nozzle shape in cold spray

Abstract

Cold spray is one of the thermal spray technologies to make a coating. From the practical point of view, the deposition efficiency, which is the ratio of the deposited mass on of the particle against the sprayed mass of the particles, is an important parameter. In the present study, the effect of the nozzle shape on the gas flow field and deposition efficiency is clarified by numerical simulation. The calculated results reveal that 1) The boundary layer separation occurs at the upstream even though the flow is accelerated immediately in the nozzle that was designed by the method of characteristics.2) The adhesion rate of a relatively small particle rises in the nozzle designed by the method of characteristics, and the adhesion rate of a relatively large particle rises in the conical nozzle.