Numerical investigations on the effect of total pressure and nozzle divergent length on the flow character and particle impact velocity in cold spraying

摘要: Abstract This study investigates the effect of total pressure ( P 0 ) and nozzle divergent length L d on flow character particle impact velocity in cold spraying. Computational fluid dynamic (CFD) approach is employed present work to achieve this objective. The simulated results indicate that significantly influence regime acceleration. With gradually increasing , exit Mach number M e firstly increases then fluctuates after exceeds a critical value, finally reaches maximum value maintains stable. Differing from V p continually goes up with due gas density which can improve drag force, but growth rate levels out gradually. Besides, it also found shows downward trend . However, as for there exists an optimal guarantee achieving Moreover, nozzles larger expansion ratio, longer. considered consequence competition between acceleration time force surface.