Pressure Drop During Condensation in Microchannels
Pressure Drop During Condensation in Microchannels
复制标题
微通道中冷凝过程中的压降
DOI：
10.1115/1.4024465
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Wang H
中科院分区：
文献类型：
--
作者：
Wang H
本文研究了特殊情况下的环形层流压降，或更准确地说，压力梯度，在微通道冷凝。这是唯一的流动状态允许完全理论的解决方案，而无需求助于实验数据。当从实验测量的或“总”压力梯度获得摩擦压力梯度时，获得解决方案并与空隙率经验公式（需要计算动量压力梯度）进行比较。迄今为止，计算和比较仅限于一种流体（R134a）、一个通道截面和一种流动条件。对于所考虑的情况下，它被发现，早期的近似模型估计空隙率同意与理论的环形流的解决方案。然而，从早期研究中使用的近似模型获得的动量压力梯度与理论环形流解给出的动量压力梯度之间存在显著差异，理论环形流解（数值上）高于所有这些模型。环空流动解表明，动量压力梯度与摩擦压力梯度相比并不小。环形流情况下的摩擦压力梯度比早先的相关式给出的要小得多。
The paper examines the special case of annular laminar flow pressure drop, or more precisely pressure gradient, during condensation in microchannels. This is the only flow regime permitting wholly theoretical solution without having recourse to experimental data. Solutions are obtained and comparisons made with empirical formulae for void fraction (needed to calculate the momentum pressure gradient) when obtaining the friction pressure gradient from experimentally measured or “total” pressure gradient. To date calculations and comparisons are restricted to one fluid (R134a), one channel section and one flow condition. For the case considered it is found that earlier approximate models for estimating void fraction agree quite well with the theoretical annular flow solutions. There is, however, significant difference between momentum pressure gradients obtained from approximate models used in the earlier investigations and that given by the theoretical annular flow solution which is (numerically) higher than all of them. The annular flow solution indicates that the momentum pressure gradient is not small in comparison with the friction pressure gradient. The friction pressure gradient in the annular flow case is appreciably smaller than given by the earlier correlations.
DOI：
--
发表时间：
1954-07
期刊：
--
影响因子：
--
作者：
H. Mickley;R. C. Ross;A. L. Squyers;W. E. Stewart
通讯作者：
H. Mickley;R. C. Ross;A. L. Squyers;W. E. Stewart