Abstract:

The interface tracking method—VOSET(coupled VolumeofFluid and Level Set method)combines the advantages and overcomes the disadvantages of VOF and Level Set.In this method, VOF was used to capture interfaces, which can completely keep the massconservation and overcome the disadvantage of massnonconservation in Level Set.A geometrical operation was used to calculate the Level Set function near interfaces, which could be used to compute the accurate curvature and smooth the discontinuous physical quantities near interfaces, then, the disadvantage of VOF, inaccuracy of curvature and bad smoothness of discontinuous physical quantities near interfaces, could be overcome.Therefore, VOSET was more accurate than VOF and Level Set.In this paper, VOSET was used to simulate the rising and coalescence of two or multigas bubbles.Mass conservation, feasibility of iterative geometric operation and stability of solution process of VOSET were analyzed for these complex twophase flow problems.

Key words: 界面追踪方法, VOSET, 复杂两相流

摘要：

界面追踪方法——VOSET（coupled VolumeofFluid and Level Set method）结合了VOF和Level Set两种方法的优点，克服了这两种方法的缺点。VOSET方法采用VOF方法捕捉两相间的界面，保持了两相间的质量守恒，克服了Level Set方法质量不守恒的缺点；利用几何计算方法计算界面附近的Level Set 函数，从而可以计算出准确的界面曲率和光顺界面附近突变的物理量，克服了VOF方法利用流体体积函数C计算界面曲率误差较大和光顺界面附近突变的物理量效果较差的缺点，因此该方法较VOF和Level Set方法更加精确。采用VOSET方法对两个及多个气泡的上升和溶并过程进行模拟，分析了复杂两相流动问题中VOSET方法的质量守恒特性、几何计算方法的可行性及求解过程的稳定性。本文的研究工作将为VOSET方法的推广应用奠定基础。

关键词: 界面追踪方法, VOSET, 复杂两相流