Ditchfield R, Olbricht W L
School of Chemical Engineering, Cornell University, Ithaca, NY 14853, USA.
J Biomech Eng. 1996 Aug;118(3):287-94. doi: 10.1115/1.2796009.
Experimental results are reported for the low Reynolds number flow of a suspension of spherical particles through a divergent capillary bifurcation consisting of a straight tube of circular cross-section that splits to form two tubes of equal diameter. The partitioning of particles between the downstream branches of the bifurcation is measured as a fraction of the partitioning of total volume (particles + suspending fluid) between the branches. Two bifurcation geometries are examined: a symmetric Y-shaped bifurcation and a nonsymmetric T-shaped bifurcation. This experiment focuses on the role of hydrodynamic interactions between particles on the partitioning of particles at the bifurcation. The particle diameter, made dimensionless with respect to the diameter of the branch tubes, ranges from 0.4 to 0.8. Results show that hydrodynamic interactions among the particles are significant at the bifurcation, even for conditions where interactions are unimportant in the straight branches away from the bifurcation. As a result of hydrodynamic interactions among particles at the bifurcation, the partitioning of particles between the branches is affected for particle volume fractions as small as 2 percent. The experimental results show that the effect of particle volume fraction is to diminish the inhomogeneity of particle partitioning at the bifurcation. However, the magnitude of this effect depends strongly on the overall shape of the bifurcation geometry, and, in particular on the angles between the branches.
报道了球形颗粒悬浮液在低雷诺数下通过发散型毛细管分叉的实验结果，该分叉由圆形横截面的直管组成，直管分成两个等直径的管。测量了分叉下游分支之间颗粒的分配情况，以其占分支之间总体积（颗粒+悬浮液）分配的比例表示。研究了两种分叉几何形状：对称的Y形分叉和不对称的T形分叉。本实验重点关注颗粒间流体动力相互作用在分叉处颗粒分配中的作用。颗粒直径相对于分支管直径无量纲化，范围为0.4至0.8。结果表明，即使在远离分叉的直管中相互作用不重要的情况下，颗粒间的流体动力相互作用在分叉处也很显著。由于分叉处颗粒间的流体动力相互作用，对于低至2%的颗粒体积分数，分支之间颗粒的分配也会受到影响。实验结果表明，颗粒体积分数的作用是减少分叉处颗粒分配的不均匀性。然而，这种影响的程度强烈取决于分叉几何形状的整体形状，特别是分支之间的角度。
