Three-dimensional numerical simulations of the particle loading effect on gas flow features for low pressure cold spray applications

This paper reports numerical investigations to develop a high quality simulation model for the Cold Spray (CS) process as part of the project, Supersonic Spray Advanced Modelling (SSAM). Cold spray is a process in which unmelted solid particles are accelerated through a De Laval nozzle toward a target surface and deposited, which avoids or minimises the detrimental effects that arise from melting. The gas flow injected allows the particles to achieve velocities up to 1000 m/s until they impact onto a substrate, bonding with plastic deformation. Analytical and numerical tools were used in the recent years to study the most important parameters of the fluid dynamic of the process. These parameters are often overestimated or non-validated, as many authors tend to neglect inter-phase couplings. The interactions between the gas flow features and particulate phase are important for the present multiphase flows, and many of the connected phenomena lack physical comprehension. For this purpose, a detailed 3D model for RANS simulations has been realised and the gas and particle dynamics in the nozzle and jet were analysed. Advancements for future computational methods are derived from this study, in order to build a comprehensive and coherent numerical model for cold spray applications.