Miscible displacements in capillary tubes .1. Experiments
Miscible displacements in capillary tubes .1. Experiments
复制标题
DOI：
10.1017/s0022112096008233
复制
发表时间：
1996-11-10
影响因子：
3.7
通讯作者：
Maxworthy, T
中科院分区：
文献类型：
--
作者：
Petitjeans, P;Maxworthy, T
已经在毛细管中进行了用粘性较小的流体（甘油-水混合物）置换粘性流体（甘油）的实验，所述粘性较小的流体可以以任何比例与甘油混溶。已经发现，对于垂直管和水平管，作为Peclet（Pe）和Atwood（At）数的函数，以及作为粘性和重力效应的相对重要性的度量的参数，在管壁上留下的粘性流体的量的诊断度量。对于大Pe和单位Δ t，这个诊断量的渐近值与在不混溶位移中发现的一致，而在Δ t的整个范围内，与第2部分（Chen & Meiburg 1966）的数值结果的一致性非常好。在平均Pe值大于1000时，存在尖锐的界面，使得可以在本结果与先前的不混溶流体实验之间进行直接比较，特别是可以评估扩散界面处的有效表面张力。还研究了重力对粘滞流体留在管壁上的量的影响，并与第二部分的结果进行了比较。已经进行了一个辅助实验，以测量纯甘油和几种甘油-水混合物之间的扩散系数的平均值，以便能够计算每个实验的代表性Peclet数，以及在稀释极限下作为甘油局部浓度的函数的局部值。
Experiments have been performed, in capillary tubes, on the displacement of a viscous fluid (glycerine) by a less viscous one (a glycerine-water mixture) with which it is miscible in all proportions. A diagnostic measure of the amount of viscous fluid left behind on the tube wall has been found, for both vertical and horizontal tubes, as a function of the Peclet (Pe) and Atwood (At) numbers, as well as a parameter that is a measure of the relative importance of viscous and gravitational effects. The asymptotic value of this diagnostic quantity, for large Pe and an At of unity, has been found to agree with that found in immiscible displacements, while the agreement with the numerical results of Part 2 (Chen & Meiburg 1966), over the whole range of At, is very good. At values of the average Pe greater than 1000 a sharp interface existed so that it was possible to make direct comparisons between the present results and a prior experiment with immiscible fluids, in particular an effective surface tension at the diffusing interface could be evaluated. The effect of gravity on the amount of viscous fluid left on the tube wall has been investigated also, and compared with the results of Part 2. A subsidiary experiment has been performed to measure both the average value of the diffusion coefficient between pure glycerine and several glycerine-water mixtures, in order to be able to calculate a representative Peclet number for each experiment, and the local value as a function of the local concentration of glycerine, in the dilute limit.