一种用于蒸发液滴气动破碎直接数值模拟的自洽体积分数方法
A consistent volume-of-fluid approach for direct numerical simulation of the aerodynamic breakup of a vaporizing drop
AI总结：
提出一种基于自洽体积分数法的直接数值模拟框架，在Basilisk求解器中实现，用于高韦伯数下蒸发液滴的气动破碎模拟，发现变形和破碎显著增强蒸发速率。
摘要：
本研究开发了一种新的模拟框架，用于对蒸发液滴的气动破碎进行直接数值模拟。采用自洽的几何体积分数方法求解带相变的界面多相流。流体为粘性不可压缩流体，界面处存在表面张力。新开发的数值方法已在Basilisk求解器中实现，该求解器采用自适应八叉树/四叉树网格进行空间离散，允许在用户定义区域内灵活地动态细化网格。该模拟框架通过一系列基准算例进行了广泛验证，包括一维Stefan问题和吸吮问题、过热液体中三维球形气泡的生长以及二维薄膜沸腾问题。模拟结果与精确解及先前的数值研究非常吻合。进行了二维轴对称模拟，以解析高温自由流中低韦伯数运动液滴的蒸发过程。计算得到的体积损失率与液滴蒸发的经验模型吻合良好。最后，使用经过验证的求解器模拟了高韦伯数下丙酮液滴的气动破碎。进行了全三维模拟，并精确解析了液滴的形态演变。研究发现，由于液滴变形和破碎，蒸发速率显著增强。液滴体积随时间非线性减小，且减小速率远高于球形液滴的经验关联式所预测的值。
英文摘要：
A novel simulation framework has been developed in this study for the direct numerical simulation of the aerodynamic breakup of a vaporizing drop. The interfacial multiphase flow with phase change is resolved using a consistent geometric volume-of-fluid method. The bulk fluids are viscous and incompressible with surface tension at the interface. The newly-developed numerical methods have been implemented in the Basilisk solver, in which the adaptive octree/quadtree mesh is used for spatial discretization, allowing flexibility in dynamically refining the mesh in a user-defined region. The simulation framework is extensively validated by a series of benchmark cases, including the 1D Stefan and sucking problems, the growth of a 3D spherical bubble in a superheated liquid, and a 2D film boiling problem. The simulation results agree very well with the exact solution and previous numerical studies. 2D axisymmetric simulations were performed to resolve the vaporization of a moving drop with a low Weber number in a high-temperature free stream. The computed rate of volume loss agrees well with the empirical model of drop evaporation. Finally, the validated solver is used to simulate the aerodynamic breakup of an acetone drop at a high Weber number. A fully 3D simulation is performed and the morphological evolution of the drop is accurately resolved. The rate of vaporization is found to be significantly enhanced due to the drop deformation and breakup. The drop volume decreases nonlinearly in time and at a much higher rate than the empirical correlation for a spherical drop.
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。
