论文标题
沉积颗粒状悬浮液的不稳定入侵
Unstable invasion of sedimenting granular suspensions
论文作者
论文摘要
当将颗粒状悬浮液径向注入到充满可信流体的细胞的水平平行板之间时，我们研究了迁移率反转和指法的发展。虽然当悬浮液和移位的流体密度完全匹配时，悬浮液会均匀地扩散，但即使发现较小的密度差也会导致一个密集的颗粒锋，该颗粒锋会随着角度间距而形成手指，随着颗粒体积分数的增加，随着注射速率的降低。我们表明，不稳定性发展的时间尺度是由晶粒中晶粒的体积分数依赖性沉降时间尺度给出的。然后，我们表明，由于颗粒体积分数梯度导致的迁移率反转和非平衡性korteweg表面张力决定了这些可行的悬浮液在不稳定性开始时的手指数量。
We investigate the development of mobility inversion and fingering when a granular suspension is injected radially between horizontal parallel plates of a cell filled with a miscible fluid. While the suspension spreads uniformly when the suspension and the displaced fluid densities are exactly matched, even a small density difference is found to result in a dense granular front which develops fingers with angular spacing that increase with granular volume fraction and decrease with injection rate. We show that the time scale over which the instability develops is given by the volume fraction dependent settling time scale of the grains in the cell. We then show that the mobility inversion and the non-equilibrium Korteweg surface tension due to granular volume fraction gradients determine the number of fingers at the onset of the instability in these miscible suspensions.
