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冷喷涂(CGDS)过程中粒子速度是决定粒子粘附性的最重要的因素之一。本文对确定进出口压力和温度边界条件下氮气(N2)在拉阀尔喷管中的流动进行了数值分析研究,并计算了粒径在100nm到50μm之间铜和铂两种金属粒子在喷管中的加速运动过程。结果表明在喷管扩张部分的出口处有圆锥状的微弱震荡(压缩波)产生;材料密度对微米尺度的粒子的加速特性有显著影响,而对纳米尺度粒子的加速行为影响不大;在相同的入口条件下,粒子越小则其在喷管出口处的速度越大。
Particle velocity during cold spray (CGDS) is one of the most important determinants of particle adhesion. In this paper, the numerical analysis of the flow of nitrogen (N2) in the lacquered nozzle under the condition of the pressure and temperature of the inlet and outlet was carried out, and the effects of spraying two kinds of metal particles of copper and platinum on the nozzle Accelerated tube movement process. The results show that there is a cone-shaped weak oscillation (compression wave) at the exit of the nozzle. The material density has a significant effect on the acceleration characteristics of the microscale particles, but has little effect on the acceleration behavior of the nanoscale particles. Of the inlet conditions, the smaller the particles, the greater the velocity at the outlet of the nozzle.