Study of the gas-particle radial supersonic jet in the cold spraying

Abstract

For the first time numerical simulation of gas and particle flow produced by a radial supersonic nozzle under conditions of cold spraying on pipe inner surface is performed. The case of a jet discharging into ambient space and its interaction with pipe internal surface is considered. It is shown that, at a certain distance from the nozzle exit, the jet becomes unstable, and bending oscillations develop in it. The velocities and trajectories of particles accelerated in the radial nozzle and jet are evaluated. For this purpose “frozen” gas flow pattern was used. The calculated data for the gas flow and particle velocity are shown to be in good agreement with available experimental data. Verified numerical model is applied for calculation of gas and particle parameters under conditions of one of successful cold spraying tests. Obtained results are discussed. It is concluded that strong non-stationary bending oscillations of radial jet lead to particle deceleration, limiting maximal pipe inner diameter.