Predicting drop size has remained an important aspect in the development of Lagrangian-Eulerian (LE) and other spray models. In the present work, the importance of drop size and spreading angle are evaluated by employing high-fidelity atomization simulations using an algebraic volume of fluid (VoF) approach (InterFoam). The process begins by extracting an axial drop size profile (D₃₂^VoF) from VoF results and imposing this profile directly on LE calculations, thereby excluding all breakup models and isolating the effect of the LE calculations on the accuracy of the spray predictions. This LE accuracy is evaluated based on comparisons to projected mass density maps generated by the VoF calculations. The results show that, even with the imposition of the D₃₂^VoF profile, the LE calculations exhibit significant errors in comparison to VoF results. This discrepancy emphasizes that having the correct breakup model in LE computations can still lead to significant errors. Additionally, the spreading angle is found to play a much more important role in the prediction of spray mass distribution in comparison to drop size. A key ingredient missing in LE calculations, which is mostly responsible for the errors observed, is the ability of the LE spray model to replicate the axially developing spreading angle, which we believe is partially based on the complex momentum transfer between the gas phase and a large population of dynamically evolving and highly nonspherical liquid elements.

中文翻译：

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在近场喷涂计算中评估液滴尺寸和扩散角的重要性

预测液滴大小仍然是拉格朗日-欧拉（LE）和其他喷雾模型开发的重要方面。在当前的工作中，通过使用流体代数体积（VoF）方法（InterFoam）进行高保真雾化模拟，可以评估液滴大小和散布角的重要性。该过程开始于从VoF结果中提取轴向液滴尺寸分布图（D ₃₂ ^VoF），并将该分布图直接应用于LE计算中，从而排除所有破裂模型并隔离LE计算对喷雾预测精度的影响。根据与VoF计算生成的投影质量密度图的比较，评估LE的准确性。结果表明，即使强加了D ₃₂ ^VoF从图可以看出，与VoF结果相比，LE计算显示出明显的误差。这种差异强调了在LE计算中具有正确的分解模型仍会导致重大错误。另外，发现与喷雾尺寸相比，散布角在喷雾质量分布的预测中起着更为重要的作用。LE计算中缺少的一个关键成分（主要是观察到的误差）是LE喷雾模型复制轴向扩展的扩展角的能力，我们认为，这部分是基于气相和气相之间复杂的动量传递。大量动态演化且高度非球形的液体元素。