摘要
针对超音速等离子喷涂过程中飞行颗粒与气流相互作用过程难以从实验获得的问题,采用数值计算方法,对以内送粉形式加入的原料颗粒的飞行状态进行跟踪分析,并利用SprayWatch-2i仪对飞行颗粒进行在线监测.计算得到了粒子的动力学和热力学行为以及撞击基体前的速度和温度分布,发现颗粒在喷涂距离为80～i00 mm的速度和温度最大,这与实验收集到的此范围内单个颗粒的形态相符,可选择此范围为最佳喷涂距离.通过分析韦伯数以及小直径颗粒的速度分布得出,在内送粉超音速等离子喷涂过程中,颗粒在喷枪内部和近出口位置会发生破碎细化和雾化,这与实验观测的结果一致.该计算及分析结果可为颗粒在射流中的传热传质研究提供参考,为获得高质量涂层提供理论依据.
To investigate the thermal and dynamic behaviors of in-flight particles in plasma flow the velocity and temperature before impinging plate,and the trajectories of particles injected by inner channel are analyzed for whole supersonic plasma flow,the actual in-flight particles are online monitored by SprayWatch-2i.Numerical test result indicates that both particle velocity and temperature achieve the maximum at the distance of 80～100 mm,which coincides with the status of observed individual particle in the experiments.So this range of 80～ 100 mm can be taken as the best spraying distance.According to the analysis for Weber number and velocity distribution of particles with small diameters,particles are melted and refined inside the gun or near the gun exit in internal powder injection supersonic plasma spray,which supports the experimental results on heat and mass transfer of particles.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2014年第6期91-97,共7页
Journal of Xi'an Jiaotong University
基金
国防"973计划"资助项目(613112-K3)
西安交通大学金属材料强度国家重点实验室开放研究项目(20131310)
关键词
等离子喷涂
内送粉
颗粒
超音速
plasma spray
inner powder injection
particle
supersonic
