A diffuse interface model for low solubility binary flows in porous media
A diffuse interface model for low solubility binary flows in porous media
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DOI：
10.1016/j.jcp.2022.111582
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
Qian Li;W. Cai;Ching-Yao Chen;E. Meiburg
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文献类型：
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作者：
Qian Li;W. Cai;Ching-Yao Chen;E. Meiburg
通过二维数值模拟和尺度分析，分析了多孔介质中自由界面分离的低溶解度流体的溶解度驱动对流。为此，我们采用了具有亥姆霍兹自由能的低溶解度Darcy-Cahn-Hilliard模型。动量方程在流函数-涡量公式中采用伪谱法求解，从而自动满足连续性；扩散方程采用显式龙格-库塔过程结合高阶紧致有限差分进行时间积分。我们通过比较表面位置标准偏差的增长率与Hele-Shaw池中co2 -水系统的实验测量值来验证模拟方法。低溶解度流体密度驱动对流流动中界面形态演变的数值结果与实验结果的吻合度明显高于相应的全溶性结果。准确地记录了界面羽流的时间演化过程，确定了具有不同羽流特征的不同阶段。讨论了低溶解度流体与完全溶解度流体在羽流特征和溶质通量方面的差异，发现低溶解度模拟方法对研究多孔岩石中co2动力学具有明显的优势。
Dissolution-driven convection of low solubility fluids separated by a free interface in a porous medium is analyzed via two-dimensional numerical simulations and scaling considerations. Towards this end, we employ a low solubility Darcy-Cahn-Hilliard model with a Helmholtz free energy. The momentum equations are solved in the stream function-vorticity formulation with a pseudospectral method, so that continuity is automatically satisfied, while the diffusion equation is integrated in time by an explicit Runge-Kutta procedure, combined with high order compact finite differences. We validate the simulation approach by comparing the growth rate of the standard deviation of the surface location with experimental measurements for a C O 2-water system in a Hele-Shaw cell. The numerical results for the evolving interfacial shape in density-driven convection flow of low solubility fluids agree significantly better with experimental observations than corresponding fully soluble results. The temporal evolution of the interfacial plumes is accurately captured, and distinct stages with different plume features are identified. The differences in plume features and solute flux of C O 2 between low solubility and fully soluble fluids are discussed, and it is found that the low solubility simulation approach offers clear advantages for the investigation of C O 2-dynamics in porous rock.