基于CFD技术的超音速喷嘴两相流破碎机制研究

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摘要采用CFD(computational fluid dynamics,计算流体力学)软件系统研究超音速气雾化喷嘴两相流的雾化过程。利用VOF(volume of fluid,流体体积)函数两相流模型模拟验证金属液不同质量流率下的2种初级破碎模式,并研究雾化压力和液体表面张力对金属液初级破碎过程的影响。模拟结果表明：金属液质量流率较小(0.053 kg/s)时,初级破碎模式为液膜破碎,金属液质量流率较大(0.265 kg/s)时,初级破碎模式为“微型喷泉”破碎;随雾化压力从0.5 MPa增加到1.5 MPa,初级破碎程度加剧,但雾化压力过高反而会削弱雾化效果;将金属液表面张力由1.2 N/m降至0.4 N/m,初级破碎时能够获得尺寸更细小的液滴,通过随后的二次破碎形成更加均匀细小的液滴,从而获得高质量的沉积锭。

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	朱玲玲
	吴建军
	刘明翔
	隋大山
	崔振山

关键词 ：喷射成形, CFD, 超音速喷嘴, 两相流, 破碎机制

Abstract：The atomization process of gas-liquid two-phase flows in ultrasonic gas atomizer was analyzed using computational fluid dynamics software. The two kinds of primary-breakup models of liquid metal at different mass flow rates were verified by volume of fluid model, and the effects of atomizing pressure and liquid surface tension on the primary-breakup process were also studied. The simulation results indicate that the transformation of primary-breakup model will occur with decreasing the liquid mass flow rate. When the liquid mass flow rate is 0.053 kg/s, the primary breakup model is melt sheet, but when it is 0.265 kg/s, the primary breakup model is “fountain”. When the atomizing pressure increases from 0.5 MPa to 1.5 MPa, the primary-breakup degree aggravates. However, excessive atomizing pressure will weaken the atomization effect. The smaller-size drop can be formed in the primary-breakup process when the surface tension of liquid metal decreases from 1.2 N/m to 0.4 N/m. Through the following secondary-breakup, more uniform and finer powder particles and high-quality as-spray ingot will be obtained.

Key words： spray forming CFD ultrasonic gas atomizer two-phase flows breakup mechanism

收稿日期: 2017-11-21 出版日期: 2019-07-12

ZTFLH:

TF123.112

基金资助:国家自然科学基金资助项目(51675335)

通讯作者: 隋大山,副教授,博士。电话：021-62813;E-mail: dasui@sjtu.edu.cn

引用本文:

朱玲玲, 吴建军, 刘明翔, 隋大山, 崔振山. 基于CFD技术的超音速喷嘴两相流破碎机制研究[J]. 粉末冶金材料科学与工程, 2018, 23(3): 229-237.
ZHU Lingling, WU Jianjun, LIU Mingxiang, SUI Dashan, CUI Zhenshan. A computational fluid dynamics (CFD) research on the atomization mechanism of two-phase flows in ultrasonic gas atomizer. Materials Science and Engineering of Powder Metallurgy, 2018, 23(3): 229-237.

链接本文:

http://pmbjb.csu.edu.cn/CN/ 或 http://pmbjb.csu.edu.cn/CN/Y2018/V23/I3/229

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