论文标题
双向耦合如何修饰多尺度优先扫描机制
How two-way coupling modifies the multiscale preferential sweeping mechanism
论文作者
论文摘要
For one-way coupled (1WC) flows, Tom & Bragg (J. Fluid Mech., 871, pp. 244-270, 2019) advanced the analysis of Maxey (J. Fluid Mech., 174, pp. 441-465, 1987), which applied to weakly inertial particles, to particles of arbitrary inertia, and the new theoretical result revealed the role that different scales play in the优先扫描机制会导致湍流中增强的粒子沉降。 Monchaux＆deJoan（Phys。Rev。Fluids，2，104302，2017）表明，使用直接数值模拟（DNS），尽管对于低粒子负荷而言，双向耦合（2WC）对全球流量统计的影响很弱，但2WC可以使颗粒在其范围内拖动，并在其范围内拖动，并在其上拖动了它们，并在他们的范围内倾斜，并在他们的范围内倾斜，并在这些方面的范围驱动了这些东西，并拖动了这些粒子，并驱动了这些粒子的范围。 机制。我们通过考虑2WC对不同大小对粒子沉降的涡流的影响进一步探讨这一点。与Monchaux＆DeJoan一致，我们表明，即使对于低负载，2WC也会强烈增强粒子沉降，并且我们显示2WC如何修改不同流量尺度的贡献。但是，与他们的研究相反，我们表明在2WC流中，优惠席位仍然很重要。特别是，对于1WC和2WC流，由于湍流而引起的沉降增强均由颗粒的颗粒中的颗粒造成的贡献支配，但是对于2WC情况，这些区域中的颗粒也与它们相比，这些区域的粒子也会使其降低，从而增强其沉降的增强。
For one-way coupled (1WC) flows, Tom & Bragg (J. Fluid Mech., 871, pp. 244-270, 2019) advanced the analysis of Maxey (J. Fluid Mech., 174, pp. 441-465, 1987), which applied to weakly inertial particles, to particles of arbitrary inertia, and the new theoretical result revealed the role that different scales play in the preferential sweeping mechanism that leads to enhanced particle settling in turbulent flows. Monchaux & Dejoan (Phys. Rev. Fluids, 2, 104302, 2017) showed using direct numerical simulations (DNS) that while for low particle loading the effect of two-way coupling (2WC) on the global flow statistics is weak, 2WC enables the particles to drag the fluid in their vicinity down with them, significantly enhancing their settling, and they argued that 2WC suppresses the preferential sweeping mechanism. We explore this further by considering the impact of 2WC on the contribution made by eddies of different sizes on the particle settling. In agreement with Monchaux & Dejoan, we show that even for low loading, 2WC strongly enhances particle settling, and we show how 2WC modifies the contribution from different flow scales. However, contrary to their study, we show that preferential sweeping remains important in 2WC flows. In particular, for both 1WC and 2WC flows, the settling enhancement due to turbulence is dominated by contributions from particles in straining regions of the flow, but for the 2WC case, the particles in these regions also drag the fluid down with them, leading to an enhancement of their settling compared to the 1WC case.
