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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CO_2浓度分布,而采用不同液相时,相同位置处正丙醇中CO_2浓度较无水乙醇及蒸馏水中CO_2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。
Due to the miniaturization of scales, the experimental research on fluid flow and mass transfer in microchannels has been greatly restricted. With the rapid development of computer technology, numerical simulation has become an important method to study and analyze complex problems. In this paper, computer-based VOF method FLUENT simulation software was used to simulate the mass transfer process of gas-liquid two-phase Taylor flow in microchannels, mainly in a single Taylor bubble and its adjacent liquid column units. By changing the simulation parameters, the effect of different factors on the mass transfer process is obtained. The results show that there is a large concentration distribution of CO 2 in the middle of the liquid column in Taylor bubble cell. When different liquid phases are used, CO 2 concentration in n-propanol in the same position is higher than that in absolute ethanol and distilled water, In the microchannel with diameter, the volumetric mass transfer coefficient increases with the increase of bubble velocity and decreases with the increase of bubble length of Taylor bubble. In the literature, the theoretical model of permeability is close to the result of this paper when the parameter m is 4.5, confirming that the mass transfer in Taylor flow mainly occurs in the liquid film.