Bolus contaminant dispersion in oscillatory tube flow with conductive walls.
Bolus contaminant dispersion in oscillatory tube flow with conductive walls.
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DOI：
10.1115/1.2895507
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发表时间：
1993-11
期刊：
影响因子：
--
通讯作者：
Y. Jiang;J. Grotberg
中科院分区：
文献类型：
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作者：
Y. Jiang;J. Grotberg
用微分展开法求解了具有振荡流动和导电壁的直管中污染物的分散问题。使用渐近方法，当存在小电导时，通过时间平均有效扩散率测量的轴向色散在绝缘情况下增加，只要无量纲频率（沃默斯利参数）α小于临界值。当α超过这个值时，轴向色散因壁电导而减弱。研究了该临界α对系统参数的泛函依赖性。我们研究了径向壁输运的总质量和局部通量，发现它们与速度场无关，并计算了随时间变化的壁输运总质量和大时间的渐近舍伍德数作为壁电导的函数。
Dispersion of a bolus contaminant in a straight tube with oscillatory flows and conductive walls is solved by using a derivative-expansion method. Using asymptotic methods when small conductance exists, the axial dispersion, as measured by the time-averaged effective diffusivity, increases over the insulated case, as long as the dimensionless frequency (Womersley parameter), alpha, is smaller than a critical value. When alpha exceeds this value, axial dispersion is diminished by wall conductance. The functional dependence of this critical alpha on the system parameters is investigated. We examine the radial wall transport both for total mass and localized flux, which is found to be independent of velocity field, and compute the time-dependent total mass of wall transport and asymptotic Sherwood number for large times as a function of the wall conductance.