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arXiv 2202.01019physics.flu-dynphysics.comp-ph
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一种改进的耦合水平集和流体体积(i-CLSVoF)框架用于液滴蒸发

An improved Coupled Level Set and Volume of Fluid (i-CLSVoF) framework for droplet evaporation

Huihuang Xia, Marc Kamlah

摘要:

表面张力主导的液滴蒸发是普遍存在的,并且对于许多应用是重要的。我们提出了一种改进的耦合水平集和流体体积(i-CLSVoF)框架,没有显式的界面重建模拟微尺寸的液滴蒸发和不蒸发。在i-CLSVoF框架下,开发并实现了一种改进的表面张力力模型,该模型具有额外的过滤步骤以过滤非物理的虚假速度。提出了一种简单而有效的基于速度势的方法来重建液滴蒸发过程中自由表面平流的无发散速度场。该方法解决了界面处蒸发诱导速度突变引起的数值问题。在这项工作中纳入的涂抹质量源项的方法保证更大的数值稳定性比非涂抹的方法。三种不同的蒸发模型(恒定质量通量,热驱动蒸发和液滴蒸发在室温下)在i-CLSVoF中实现。通过算例分析,验证了表面张力和蒸发模型的正确性。数值解和相应的解析解之间的一致性很好,在这项工作中开发的模型显示出令人信服的性能,在模拟表面张力为主的流动和不蒸发。

英文摘要:

Surface-tension-dominant droplet evaporation is ubiquitous and of importance to many applications. We present an improved Coupled Level Set and Volume of Fluid (i-CLSVoF) framework without explicit interface reconstruction for modelling micro-sized droplets with and without evaporation. In the i-CLSVoF framework, an improved surface tension force model with additional filtering steps to filter un-physical spurious velocities is developed and implemented. A simple, yet efficient, velocity-potential based approach is proposed to reconstruct a divergence-free velocity field for the advection of the free surface during droplet evaporation. This approach fixes the numerical issues resulting from the evaporation-induced velocity jump at the interface. The smeared mass source term approach incorporated in this work guarantees greater numerical stability than the non-smeared approach. Three different evaporation models (constant mass flux, thermally driven evaporation and droplet evaporation at room temperature) are implemented in the i-CLSVoF. Corresponding numerical benchmark cases (dam break, droplet relaxation and droplet evaporation subjected to different evaporation models) are conducted to validate the surface tension and the evaporation models. Good agreement between the numerical and corresponding analytical solutions is found. The model developed in this work shows convincing performance in modelling surface-tension-dominant flow with and without evaporation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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