直流喷射首次破碎的形变过程研究
发布时间：2019-01-02 13:40
【摘要】：为深入了解直流喷射过程中射流柱的细部结构以及其脱落过程,利用LES结合VOF的方法,对静止大气中垂直射流现象进行模拟。模拟得到的液相喷雾结构和试验结果能够很好地吻合。通过计算观察得到射流柱进入到大气中后由于Rayleigh-Taylor(RT)不稳定性迅速形成伞状的头部,头部的边缘在不断变薄失稳的过程中脱落形成液带,液带脱落产生的液滴具有等距性,间距为0.106mm,并在伞状边缘的下方形成一个气涡,气涡与上游的射流柱相互作用,促进射流柱表面的脱落。射流柱表面由于Kelvin-Helmholtz(K-H)表面波的作用呈现鱼鳞状的结构,并导致射流柱整体断裂、破碎,其表面波波长由初始的0.26mm迅速增长到0.78mm。
[Abstract]:In order to understand the detail structure of jet column and its shedding process in DC jet process, the vertical jet phenomenon in static atmosphere was simulated by LES and VOF. The simulated liquid spray structure is in good agreement with the experimental results. After the jet column enters the atmosphere, it is observed that due to the rapid formation of the umbrella head due to the Rayleigh-Taylor (RT) instability, the edge of the head falls off and forms a liquid belt during the process of thinning and instability. The droplets produced by the strip shedding are equidistant with a distance of 0.106 mm, and a vortex is formed below the umbrella edge, which interacts with the upstream jet column to promote the surface shedding of the jet column. Due to the action of Kelvin-Helmholtz (K-H) surface waves, the jet column surface presents a fish scale structure, which leads to the fracture and fragmentation of the jet column as a whole. The wave length of the jet column increases rapidly from the initial 0.26mm to 0.78 mm.
【作者单位】： 西北工业大学动力与能源学院;中国空气动力研究与发展中心高超中心;
【分类号】：V231
，
本文编号：2398562
[Abstract]:In order to understand the detail structure of jet column and its shedding process in DC jet process, the vertical jet phenomenon in static atmosphere was simulated by LES and VOF. The simulated liquid spray structure is in good agreement with the experimental results. After the jet column enters the atmosphere, it is observed that due to the rapid formation of the umbrella head due to the Rayleigh-Taylor (RT) instability, the edge of the head falls off and forms a liquid belt during the process of thinning and instability. The droplets produced by the strip shedding are equidistant with a distance of 0.106 mm, and a vortex is formed below the umbrella edge, which interacts with the upstream jet column to promote the surface shedding of the jet column. Due to the action of Kelvin-Helmholtz (K-H) surface waves, the jet column surface presents a fish scale structure, which leads to the fracture and fragmentation of the jet column as a whole. The wave length of the jet column increases rapidly from the initial 0.26mm to 0.78 mm.
【作者单位】： 西北工业大学动力与能源学院;中国空气动力研究与发展中心高超中心;
【分类号】：V231
，
本文编号：2398562
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