Numerical simulation study of nozzle flow field during cold spraying

Abstract Cold spraying is a high-velocity solid-state coating technology. The supersonic jet flow field, accelerated within the cold spraying nozzle, directly affects the coating results, making the study of the nozzle’s internal flow field crucial. This thesis employs Fluent software to establish a finite element simulation model of the gas-solid flow field within the Laval nozzle in cold spraying. The dynamic simulation analyzes the changes in the flow field of nitrogen gas and 7075 aluminum alloy particles inside the nozzle. The simulation results reveal that the gas phase velocity continuously increases within the nozzle; the turbulent kinetic energy of the gas initially increases and then decreases within the nozzle; the relationship between the spraying velocities of the gas and particles of different sizes within the nozzle is also determined.