Near wall interaction in spray impingement
Near wall interaction in spray impingement
复制标题
喷雾冲击中的近壁相互作用
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
J. Senda
中科院分区：
文献类型：
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作者：
M. Al;P. Farrell;J. Senda
固体表面上的液滴-液滴和液滴-液膜相互作用的流体动力学细节被认为在喷雾撞击现象中具有重要作用，但这种相互作用的细节尚未被清楚地确定。液滴之间的相互作用在冲击期间影响它们在表面上的停留时间、铺展以及液滴和液膜稳定性。撞击后，液滴相互作用影响液滴碰撞、聚结和液体飞溅。这种相互作用影响二次雾化和撞击过程的液滴分散特性。在这项研究中，液滴-液滴和液滴-液膜相互作用的固体表面撞击的细节已经可视化使用高速摄影。这些相互作用对二次雾化和液滴分散的影响已被量化。精确间隔的液滴的paramentals撞击在加热的表面上，包裹的特征在于时间和长度尺度，并通过它们的空隙率。冲击表面温度的变化，以检查不同的传热制度，从饱和通过核沸腾膜沸腾。本研究的结论是，对于在饱和状态下形成的液膜，液膜破碎取决于撞击液滴的能量含量，液膜表面扰动的水平和液膜厚度。在过渡区和膜态沸腾区，三个主要变量影响相互作用过程：包裹结构（液滴数和间距）、韦伯数和表面张力。«少
The hydrodynamic details of droplet-droplet and droplet-liquid film interactions on solid surfaces are believed to have a significant role in spray impingement phenomena, yet details of this interaction have not been clearly identified. The interaction among the droplets during impact affects their residence time on the surface, spreading, and droplet and liquid film stability. After impact, droplet interactions affect droplet collisions, coalescence and liquid splashing. This interaction affects secondary atomization and the droplet dispersion characteristics of the impingement process. In this study, details of droplet-droplet and droplet-liquid film interactions in solid surface impingement have been visualized using high speed photography. The effects of these interactions on secondary atomization and droplet dispersion have been quantified. Parcels of accurately spaced droplets were impinged on a heated surface and the parcels were characterized by time and length scales and by their void fraction. The impingement surface temperature was varied to examine different heat transfer regimes, from saturation through nucleate boiling to film boiling. This study concludes that for the liquid films formed in the saturation regime, liquid film breakup depends on the impinging droplet(s) energy content, the level of the liquid film surface disturbance and on the liquid film thickness. In the transitionmore » and film boiling regimes three major variables affect the interaction process: parcel configuration (droplet number and spacing), Weber number and surface superheat.« less