Direct numerical simulation of reactive absorption in gas-liquid flow on structured packing using interface capturing method
Direct numerical simulation of reactive absorption in gas-liquid flow on structured packing using interface capturing method
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DOI：
10.1016/j.ces.2009.07.018
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发表时间：
2010-01-01
影响因子：
4.7
通讯作者：
Raynal, L.
中科院分区：
文献类型：
--
作者：
Haroun, Y.;Legendre, D.;Raynal, L.
为了研究规整填料上气液两相流动中的物理和反应吸收，进行了直接数值模拟。采用流体体积法捕捉气液界面运动。质量传输是通过额外的化学物质浓度传输方程计算的，并对溶解度和化学反应进行了适当的建模。由于溶解度的不同，在界面处施加化学浓度跳跃间断的数值计算困难。本文采用两相流连续介质力学模型和常系数亨利定律，解决了这一难题。本研究表明，质量传递是如何受到这里考虑的复杂几何形状和流动条件的影响。结果表明：Higbie理论能较好地预测液侧传质，在采用真实的界面速度时，界面附近典型体积元的暴露时间对应于界面特征长度与界面速度之比。对于所考虑的几何形状，转移被发现是增加相比，平面液膜的转移。最后，对于液相中伴有二级不可逆化学反应的传质情况，将数值结果与Brian等[1961]提出的近似解进行了比较。二级化学反应气体吸收的穿透理论。A.I.Ch.E. J. 7，226-231]，并观察到良好的一致性。(C)2009爱思唯尔有限公司版权所有。
Direct numerical simulations are performed in order to study physical and reactive absorption in gas-liquid flow on structured packing. The volume of fluid method is used to capture the gas-liquid interface motion. The mass transport is computed by additional chemical species concentration transport equation with adequate modelling of solubility and chemical reaction. The numerical difficulties arise in imposing jump discontinuity for chemical concentrations at the interface due to different solubility. These difficulties are solved by an original method using a continuum mechanical modelling of two phases flow and Henry's law with constant coefficient. The present study shows how the mass transfer is affected by the complex geometry considered here and by the flow conditions. The results show firstly that the liquid side mass transfer is well predicted by the Higbie theory and the exposure time of a typical element of volume near the interface corresponds to ratio between characteristic length and velocity of the interface provided that the real velocity of the interface is used. For the considered geometry, the transfer is found to be increased compared to the transfer of a plane liquid film. Finally, for the case where the mass transfer is accompanied by second order irreversible chemical reaction in the liquid phase, the numerical results are compared to approximate solution presented by Brian et al. [1961. Penetration theory for gas absorption accompanied by a second order chemical reaction. A.I.Ch.E. J. 7, 226-231] and good agreement is observed. (C) 2009 Elsevier Ltd. All rights reserved.