干旱区生态环境知识资源中心(Arid): 真空度对真空冷喷涂气固两相流的影响

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	真空度对真空冷喷涂气固两相流的影响
其他题名	Influence of Vacuum Degree on Gas-Solid Flow in Vacuum Cold Spray
	郑建新; 郝婉君
来源期刊	表面技术
ISSN	1001-3660
出版年	2015
卷号	44 期号:12 页码:75-79,121
中文摘要	目的真空度直接影响着真空冷喷涂时气体流动特性和颗粒撞击速度,研究真空度对气体和颗粒流动特性的影响。方法确定真空冷喷涂系统结构,采用FLUENT软件进行真空冷喷涂气固两相流研究,通过数值模拟研究真空度对流场和颗粒撞击速度的影响,并研究相同压力比下的气固两相流特性。结果当入口压力一定时,喷管内的气体轴线速度、密度和温度与环境压力大小无关;而在射流区,环境压力越小,则气体轴线速度波动越小、密度越低,但到达基板后的气体温度均接近喷管入口温度。环境压力对大粒径颗粒的撞击速度影响较大,颗粒撞击速度随环境压力增大而先增后减,最佳环境压力可根据气相云图和气体密度来确定。当进出口压力比相同时,喷管内和射流区域内的气相速度云图基本相同,气体轴线速度曲线基本重合,而基板前的颗粒速度不同,此时环境压力越低,颗粒速度越高,越有利于形成涂层。结论采用计算流体动力学分析方法厘清了真空度对真空冷喷涂气固两相流的影响,为涂层制备奠定了理论基础。
英文摘要	Objective The flow behavior of gas and the particle impact velocity are directly affected by the vacuum degree in the process of vacuum cold spray. The influences of vacuum degree on gas and particle flow properties were studied. Methods The structure of the vacuum cold spray system was determined, and the gas-solid flow in vacuum spray was studied based on FLUENT. The influences of vacuum degree on the flow field and particle impact velocity were explored through numerical simulation, and the gas-solid flow properties under the same pressure ratio were studied. Results The numerical research indicated that when the inlet pressure was constant,the axis velocity, the density and the temperature of gas in the nozzle were independent of the ambient pressure ,whereas in the jet flow region,lower ambient pressure led to lower fluctuation of the gas velocities and lower gas density. However, when the gas reached the substrate, its temperature was close to the inlet temperature in all cases. The ambient pressure had obvious effect on the impact velocity of the particle with large diameter, and the impact velocity first increased and then decreased with increasing ambient pressure, and the optimal ambient pressure could be determined by the gas contour and its density. When the pressure ratios of the inlet and outlet of the nozzle were the same,the gas contours in the nozzle arid the jet flow region were almost the same,and the curves of the gas axis velocities almost coincided. While the particle velocities before the substrate were different, the lower the ambient pressure, the higher the particle velocity, which was more beneficial to coating formation. Conclusion The influence of vacuum degree on the gas-solid flow in vacuum spray was clarified based on the CFD,which laid the ground work for the preparation of coating.
中文关键词	真空冷喷涂 ; 气固两相流 ; 真空度 ; 流场 ; 颗粒速度 ; 数值研究
英文关键词	vacuum cold spray gas-solid flow vacuum degree flow field particle velocity numerical research
语种	中文
国家	中国
收录类别	CSCD
WOS类目	METALLURGY METALLURGICAL ENGINEERING ; ENGINEERING CHEMICAL
WOS研究方向	Metallurgy & Metallurgical Engineering ; Engineering
CSCD记录号	CSCD:5604989
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/232356
作者单位	河南理工大学机械与动力工程学院, 焦作, 河南 454003, 中国
推荐引用方式 GB/T 7714	郑建新,郝婉君. 真空度对真空冷喷涂气固两相流的影响[J],2015,44(12):75-79,121.
APA	郑建新,&郝婉君.(2015).真空度对真空冷喷涂气固两相流的影响.表面技术,44(12),75-79,121.
MLA	郑建新,et al."真空度对真空冷喷涂气固两相流的影响".表面技术 44.12(2015):75-79,121.