论文标题
使用离散的统一气体动力学方案以较大密度比和高雷诺数的仿真两相流量
Simulation of two-phase flows at large density ratios and high Reynolds numbers using a discrete unified gas kinetic scheme
论文作者
论文摘要
为了以较大的密度比和较高的雷诺数处理不混溶的两相流，开发了基于离散的统一气体动力学方案（DUGKS）的三维代码，并结合了两个重大改进。首先，使用加权基本上非振荡方案重建细胞界面的粒子分布函数。其次，选择保守的下阶艾伦 - 卡纳方程，而不是高阶Cahn-hilliard方程，以进化基于自由能的相位场，控制了两相接口的动力学。模拟了五个基准问题，以证明该方法以较高的密度比和较高的雷诺数处理两个相流的能力，包括三个二维问题（一个固定的液滴，雷利 - 泰勒的不稳定，以及在稀薄的液体膜上滴水）和两种三维问题（binarylights collimions collimish collimigh-taylorigh-taylor instobility collighigh-instobility）。所有结果都与先前的数值和实验结果一致。在这些模拟中，密度比和雷诺数可以达到O（1000）的较大值。我们改进的方法为Dugks方案奠定了阶段，以处理现实的两相流问题。
In order to treat immiscible two-phase flows at large density ratios and high Reynolds numbers, a three-dimensional code based on the discrete unified gas kinetic scheme (DUGKS) is developed, incorporating two major improvements. First, the particle distribution functions at cell interfaces are reconstructed using a weighted essentially non-oscillatory scheme. Second, the conservative lower-order Allen-Cahn equation is chosen, instead of the higher-order Cahn-Hilliard equation, to evolve the free-energy based phase field governing the dynamics of two-phase interfaces. Five benchmark problems are simulated to demonstrate the capability of the approach in treating two phase flows at large density ratios and high Reynolds numbers, including three two dimensional problems (a stationary droplet, Rayleigh-Taylor instability, and a droplet splashing on a thin liquid film) and two three-dimensional problems (binary droplets collision and Rayleigh-Taylor instability). All results agree well with the previous numerical and the experimental results. In these simulations, the density ratio and Reynolds number can reach a large value of O(1000). Our improved approach sets the stage for the DUGKS scheme to handle realistic two-phase flow problems.
