A VARIABLE-DENSITY PROJECTION METHOD FOR INTERFACIAL FLOWS
A VARIABLE-DENSITY PROJECTION METHOD FOR INTERFACIAL FLOWS
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DOI：
10.1080/716100497
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发表时间：
2003-12
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影响因子：
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通讯作者：
M. Ni;M. Abdou;S. Komori
中科院分区：
文献类型：
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作者：
M. Ni;M. Abdou;S. Komori
本文发展了一般的二阶、变密度、三步和四步投影方法来模拟非定常不可压界面流动。提出了一种高精度变密度RKCN投影方法，该方法采用三步低存储Runge-Kutta技术和二阶半隐式Crank-Nicholson技术分别对对流项和扩散项进行时间更新.为了减少计算量，本文还提出了一种简化的投影方法，即只在最后一个子阶段求解压力泊松方程（PPE）。采用水平集方法隐式地捕捉下降液滴流动的界面。用本文方法对封闭小通道内三维气泡上升流和二维液滴下降流进行了数值研究。通过有效压力的定义，讨论了不同密度比、粘度比、韦伯数和雷诺数下液滴下落流动的流动机理。
General second-order, variable-density, three-step and four-step projection methods are developed to simulate unsteady incompressible interfacial flows. A high-accuracy, variable-density RKCN projection method is presented, in which the three-stage, low-storage Runge-Kutta technique and second-order semi-implicit Crank-Nicholson technique are employed to temporally update the convective and diffusion terms, respectively. To reduce computation cost, a simplified version of the projection method is also presented, in which the pressure Poisson equation (PPE) is solved only at the last substage. The level set approach is employed to implicitly capture the interface for falling droplet flows. Three-dimensional bubble rising flows and two-dimensional falling droplet flows in a small closed channel are studied numerically via the present method. By the definition of the effective pressure, the flow mechanisms for falling droplet flows with different density ratios, viscosity ratios, Weber numbers, and Reynolds numbers are discussed.