蒸发液滴内部非稳态流动的数值计算

发布时间：2017-12-28 06:00

本文关键词：蒸发液滴内部非稳态流动的数值计算　出处：《热科学与技术》2017年04期 　论文类型：期刊论文

【摘要】：在气液两相流VOF(volume of fluid,VOF)模型的基础上耦合CSF(continuum surface force,CSF)表面张力模型,建立了高温平板上的铺展液滴与高温空气中悬浮液滴蒸发过程中内部非稳态流动模型,对液滴蒸发过程中内部非稳态流动进行了研究。基于相变理论,采用用户自定义函数将流体相变模型加入非稳态流动模型中进行耦合计算,获得了高温平板上的铺展液滴与高温空气中悬浮液滴蒸发过程中的内部流动及变化过程。液滴蒸发过程中非稳态内部流动由液滴表面的温度梯度引发,Marangoni流动在液滴内部形成的时间非常短,流体从液滴表面高温区域流向低温区域。计算结果表明:高温平板上随着液滴蒸发的进行,液滴内部一直保持两个对称的涡流,Marangoni流动比较稳定;高温空气环境中随着液滴蒸发的进行,液滴内部四个涡流逐渐转变成两个对称的涡流;液滴内部温度分布因Marangoni流动加强传热而变得均匀,同时由于温度分布变得均匀,Marangoni流动被削弱。
[Abstract]:In the gas-liquid two-phase flow VOF (volume of fluid, VOF) coupled model based on CSF (Continuum surface force, CSF) surface tension model is established on a hot plate of the spreading droplet and the unsteady flow model in high temperature air suspended droplet evaporation process, the unsteady flow of droplet evaporation process is studied. Based on phase transition theory, user defined function is applied to calculate the fluid phase transition model in the unsteady flow model, and the internal flow and the change process of the droplet droplet and the droplet evaporation process in high temperature air are obtained. During the droplet evaporation process, the unsteady internal flow is initiated by the temperature gradient on the droplet surface. The time of Marangoni flow in the droplet is very short, and the fluid flows from the high temperature area of the droplet surface to the low temperature region. The calculation results show that the high temperature plate with droplet evaporation, droplet has maintained two symmetrical vortex flow, Marangoni is relatively stable; high temperature environment with droplet evaporation, droplet four vortex gradually transformed into two symmetrical vortex; inside the droplet temperature distribution for Marangoni flow to strengthen the heat transfer and becomes uniform, and because the temperature distribution becomes uniform, Marangoni flow is weakened.
【作者单位】：江苏大学能源与动力工程学院;国立庆尚大学机械与航空学院;
【基金】：国家自然科学基金资助项目(51106064,11502097) 江苏省自然科学基金资助项目(BK20171301) 江苏省高校优势学科建设工程资助项目
【分类号】：O35
【正文快照】： 0引言单液滴蒸发是一种典型的气液传热传质过程,是详细研究和探讨液体蒸发过程的基础。液滴蒸发的过程广泛存在于工农业生产的诸多领域,特别是存在于液体雾化与喷雾应用的各个生产环节,如喷雾降温与冷却、燃油雾化燃烧等[1-2]。关于液滴蒸发的研究主要分为两部分:一是液体蒸发

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