Additional pressure drop at a bifurcation due to the passage of flexible disks in a large scale model.
Additional pressure drop at a bifurcation due to the passage of flexible disks in a large scale model.
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由于大型模型中软盘的通过而导致分叉处的额外压降。
DOI：
10.1115/1.2895801
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Cokelet,GR
中科院分区：
文献类型：
--
作者：
Kiani,MF;Cokelet,GR
在大规模系统中对红细胞（RBC）通过微血管毛细血管分叉的流动进行建模，其中刚性圆管和分叉（直径= 0.95cm）模拟毛细血管和毛细血管分叉，柔性盘（未变形直径= 0.75cm）模拟RBC和甘油模拟血浆。在低雷诺数（0.01至0.1），压降测量在管的上游和下游的分叉，以及跨越分叉本身，在分叉处的各种流动分裂，而在上游管的流入量保持不变。如果由于流体和圆盘的分隔而在分叉处产生的附加压降可以忽略不计，则跨分叉处的压力梯度取为上游和下游压力梯度的平均值。对于甘油单独的情况，分叉处的压力梯度（G）与上游区域的压力梯度（G）的比值总是大于预期，并且当侧分支中的流量为零时达到1.14。随着柔性圆盘的引入，当圆盘接触或接近分叉的分界线并在进入分叉的一侧或另一侧之前短暂停留时，分叉处的G是上游区域G的10倍。最大的G是在分叉处均匀分流的情况，最小的G是在侧分支中的流量最小的情况。因此，对于此处测试的试管血细胞比容（0- 30%）和分流范围，观察到分叉处的显著额外压降。
The flow of red blood cells (RBC) through a microvascular capillary bifurcation was modeled in a large scale system in which rigid circular tubes and bifurcations (diameter = .95 cm) simulated capillaries and capillary bifurcations, flexible disks (undeformed diameter = 0.75 cm) simulated RBC and glycerol simulated plasma. At low Reynolds numbers (0.01 to 0.1), pressure drop was measured in the tubes upstream and downstream from the bifurcation as well as across the bifurcation itself, for various flow splits at the bifurcation while the inflow in the upstream tube was held constant. Pressure gradient across the bifurcation is taken to be the average of the upstream and downstream pressure gradients if the additional pressure drop at the bifurcation due to the partitioning of flow and disks is negligible. For the case of glycerol alone, the ratio of pressure gradient (G) at the bifurcation to the one at the upstream region was always greater than expected and reached 1.14 when the flow in the side branch was zero. With introduction of flexible disks into the system, G at the bifurcation was as much as 10 times the G at the upstream region as disks came in contact with, or close to, the dividing line of the bifurcation and paused momentarily before they entered one or the other side of the bifurcation. The largest G was for even flow split at the bifurcation and the smallest G was for the case where the flow in the side branch was smallest. Therefore, for the range of tube hematocrits (0–30 percent) and flow splits tested here, a significant additional pressure drop at the bifurcation is observed.