化工学报 ›› 2016, Vol. 67 ›› Issue (6): 2291-2299.DOI: 10.11949/j.issn.0438-1157.20151874

• 流体力学与传递现象 • 上一篇    下一篇

液体中可压缩气体射流的瞬态特性

王超, 施红辉, 汪剑锋   

  1. 浙江理工大学机械与自动控制学院, 浙江 杭州 310018
  • 收稿日期:2015-12-10 修回日期:2016-03-15 出版日期:2016-06-05 发布日期:2016-06-05
  • 通讯作者: 施红辉
  • 基金资助:

    国家自然科学基金项目(10802077);浙江理工大学流体工程技术创新团队项目(11132932611309)。

Transient characteristics of compressible gas jet in liquid

WANG Chao, SHI Honghui, WANG Jianfeng   

  1. Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, China
  • Received:2015-12-10 Revised:2016-03-15 Online:2016-06-05 Published:2016-06-05
  • Supported by:

    supported by the National Natural Science Foundation of China (10802077) and the Fluid Engineering Innovation Team of Zhejiang Sci-Tech University (11132932611309).

摘要:

针对水下超声速气体射流实验装置,分别采用高速摄影对水下超声速气体射流的形态及发展过程进行了可视化观察分析,采用VOF方法建立了二维轴对称两相数值计算流模型,对实验工况进行数值模拟,得到详细的水下超声速射流流场结构。两者结合得以研究水下气体超声速射流的形态及发展过程。研究结果表明:超声速水下射流流场明显包含射流区、过渡区和羽流区3个不同特征区域,射流区内气相的胀鼓和回击现象导致了严重的振荡流模式。气液界面不稳定性引起射流局部颈缩,从而引起颈缩上游气相截面的扩张、收缩甚至断流。可观测的小幅度的颈缩导致上游的胀鼓现象;稍大幅度的颈缩导致上游的回击现象;大幅度的颈缩甚至导致射流中断,并在随后重建射流。

关键词: 气液两相流, 数值模拟, 实验验证, 可压缩气体射流, 流动振荡

Abstract:

A device of submerged supersonic gas jet is configured and a two-dimensional axis-symmetric model of two-phase flow is established via volume of fluid (VOF) method. The flow field of the submerged supersonic gas jet is experimentally visualized using a photographic technique which allows simultaneous analysis of the jet interface to investigate the behavior of gas jets injected into water ambient. The detailed internal structure of the flow field is obtained by numerical technique via finite volume method (FVM). The results show that the flow field from the nozzle exit to the far away field of downstream includes three different characteristic regions: the jet region, the transition region and the plume region. The gravity can be ignored in jet region. And the bulge and back-attack phenomena lead to the heavy oscillation flow pattern. Gas-liquid interface instabilities cause jet necking phenomena which leads expand or pinch-off of the gas jet and subsequent bulge and back-attack phenomena. A small scale of the necking results in the bulge phenomenon at upstream. A slightly larger scale of the necking causes the back-attack phenomenon. A large scale of necking even leads to the jet pinch-off phenomenon and then jet rebuilding.

Key words: gas-liquid flow, numerical simulation, experiment validation, compressible gas jet, flow oscillation

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