【摘要】 由于尺度的微型化,微型通道内流体流动以及传质过程的实验研究受到巨大限制,随着计算机技术的快速发展,数值模拟已经成为研究分析复杂问题的重要方法。本文采用计算机VOF方法 FLUENT模拟软件对微通道内气液两相Taylor流型的传质过程进行模拟,主要集中在单个Taylor气泡及其前后相邻的液柱单元内进行。通过更改模拟参数,得到不同因素对传质过程的影响结果。结果表明,Taylor气泡单元中液柱径向中间部分存在较大的CO₂浓度分布,而采用不同液相时,相同位置处正丙醇中CO₂浓度较无水乙醇及蒸馏水中CO₂浓度大,在不同管径的微通道中,液相侧体积传质系数均随着气泡速率的增大而增加,随着Taylor气泡单元长度的增加而减小。文献中渗透理论模型在参数m取值为4.5时的计算结果与本文结果比较接近,证实了Taylor流动中的传质主要发生在液膜中。更多还原

【Abstract】 Experimental research of flow and mass transfer process in microchannel was great limited by the miniaturization of scale, while with the rapid development of computer technology, numerical simulation has become an favorable method for resolving complex problem, the computer VOF method FLUENT simulation software was adopted in this paper for simulating the mass transfer process of Taylor flow in microchannel, which mainly concentrated in a single Taylor bubble and its adjacent liquid column cell. The influences of different factors on the mass transfer process were obtained by changing the simulation parameters, and the results shows that, larger CO₂ concentration distribution exists in the middle part of the liquid column in radial, when using different liquid phases, the CO₂ concentration in n-propyl is larger than anhydrous ethanol and distilled water at the same location, in microchannels of different diameter, liquid side volumetric mass transfer coefficient increases with the bubble rate increasing while decreases with Taylor bubble length. The calculated results of penetration model at the value of the parameter m is 4.5 and the results in this paper were very close, which confirmed the mainly mass transfer occurs in the liquid film of the Taylor flow.更多还原