论文标题
中央命令离散的统一气体运动方案，用于较大密度比的不可压缩的两相流动
Central-moment discrete unified gas-kinetic scheme for incompressible two-phase flows with large density ratio
论文作者
论文摘要
在本文中，我们提出了一个中央力矩离散的统一气动方案（DUGKS），用于具有较大密度比和较高雷诺数的多相流。使用两组具有基于中央矩的多个松弛时间碰撞操作员的动力学方程来近似不可压缩的Navier-Stokes方程和用于接口捕获的保守相位场方程。在Dugks的框架中，流体动力方程的分布函数的第一瞬间定义为速度而不是动量。同时，还适当地定义了分布函数和外力的零矩，以便可以恢复人工压力进化方程。此外，采用了时间整合的Strang分裂技术来避免在细胞面上的力项中计算空间衍生物。对于接口捕获方程，介绍了两个等效的Dugks方法，它们使用源项以及修改的平衡分布函数以不同的方式处理扩散项。随后进行了几项基准测试，这些测试涵盖了广泛的密度比（最高1000）和雷诺数（最高$ 10^5 $），以证明拟议方案的功能。数值结果与参考和实验数据非常吻合。
In this paper, we proposed a central moment discrete unified gas-kinetic scheme (DUGKS) for multiphase flows with large density ratio and high Reynolds number. Two sets of kinetic equations with central-moment-based multiple relaxation time collision operator are employed to approximate the incompressible Navier-Stokes equations and a conservative phase field equation for interface-capturing. In the framework of DUGKS, the first moment of the distribution function for the hydrodynamic equations is defined as velocity instead of momentum. Meanwhile, the zeroth moments of the distribution function and external force are also suitably defined such that a artificial pressure evolution equation can be recovered. Moreover, the Strang splitting technique for time integration is employed to avoid the calculation of spatial derivatives in the force term at cell faces. For the interface-capturing equation, two equivalent DUGKS methods that deal with the diffusion term differently using a source term as well as a modified equilibrium distribution function are presented. Several benchmark tests that cover a wide a range of density ratios (up to 1000) and Reynolds numbers (up to $10^5$) are subsequently carried out to demonstrate the capabilities of the proposed scheme. Numerical results are in good agreement with the reference and experimental data.
