摘要
基于新开发的内送粉高效能超音速等离子体喷枪,本文建立内送粉全三维计算模型,利用数值方法、氩等离子体的性质、枪内工作等离子体的电离与复合反应等研究喷枪内外部多物理场下的高温高速等离子体气流特性.从得到的计算结果可以看出,喷枪内部的高温区主要在阴极附近,且呈现出三维不对称分布,内送粉结构的喷枪使得主气在经过送粉口后中心最高温度偏离轴线1 mm左右,而气流的速度分布也受内送粉气流的影响使其偏离中心轴线并在喷枪口外出现较强的速度梯度.从喷枪内的氩离子分布可以看出,从送粉口加入的粉末颗粒有带电的可能.
Based on newly developed high efficiency supersonic spraying gun,a relatively three dimensional computational model is built to investigate multi-physic plasma flow in and out of the spraying gun.Numerical method considering argon plasma properties is applied.The plasma reaction including ionization and recombination were taken into consideration,so the number density of argon ion was gotten.According to the results,the highest temperature zone in the gun appeared near the cathode tip and didn＇t behave symmetry.Since the particle carrier channel is set inside of the spraying gun,the high temperature zone was diverged from the axis for about 1 mm.Simultaneously,the velocity distribution was also influenced with high velocity zone diverging from the axis and have strong gradient out of gun.From the distribution of ion number density,the solid particles introduced into the main flow were properly charged.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2013年第2期137-148,共12页
Materials Science and Technology
基金
国家自然科学基金资助项目(50975227)
全国博士学位论文作者专项资助项目(FANEDD200740)
国家重点基础研究发展计划资助项目(2007CB707702
613112-K3)
关键词
热喷涂
内送粉
多物理场
数值分析
等离子体
thermal spray
internal powder injection
multi-physic field
numerical method
plasma spraying
