Rong F W, Carr R T
Department of Chemical Engineering, University of New Hampshire, Durham 03824-3591.
Microvasc Res. 1990 Mar;39(2):186-202. doi: 10.1016/0026-2862(90)90069-4.
This study was aimed at identifying the shape of the separating surface at the junction of two vessels and determining the shift in concentration profiles due to streamline bending at the junction. These data are useful in modeling phase separation during plasma skimming in serial microvascular bifurcations. It was hypothesized that the separating surface shape should be a function of the ratio of the branch diameters and the fractional flow split at the junction. Streamlines bend as blood flows through a junction thereby disturbing the concentration profile of several blood components downstream from the branch point. Model experiments have been conducted to test these ideas. Scaled-up dye studies have shown that the separating surface is indeed a function of the branch diameter ratio. When all branches have the same diameter the separating surface is virtually flat. When the side branch diameter is half that of the parent branch, the surface is curved, bulging away from the opening of the side branch. At Reynold's numbers greater than 20, when vortices form in the daughter branches, the shape of the separating surface is complicated and may even be discontinuous. Other dye experiments have been used to illustrate the magnitude of streamline bending. The data are then used to estimate the shift in concentration profiles due to flow through junctions. A technique for mapping upstream profiles to their corresponding downstream location has been developed. This mapping technique provides the necessary initial condition for the equation which describes the dispersion of red blood cells as they flow between the junctions.
本研究旨在确定两根血管交界处分离面的形状，并确定由于交界处流线弯曲导致的浓度分布变化。这些数据对于模拟串联微血管分支中血浆撇除过程中的相分离很有用。研究假设分离面的形状应该是分支直径比和交界处分流比的函数。当血液流经交界处时，流线会弯曲，从而扰乱分支点下游几种血液成分的浓度分布。已进行模型实验来验证这些想法。放大的染料研究表明，分离面确实是分支直径比的函数。当所有分支直径相同时，分离面实际上是平的。当侧支直径是主支直径的一半时，表面是弯曲的，从侧支开口处鼓起。在雷诺数大于20时，当子分支中形成漩涡时，分离面的形状会变得复杂，甚至可能是不连续的。其他染料实验已用于说明流线弯曲的程度。然后利用这些数据来估计由于流经交界处而导致的浓度分布变化。已开发出一种将上游分布映射到其相应下游位置的技术。这种映射技术为描述红细胞在交界处之间流动时扩散的方程提供了必要的初始条件。
