• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Journal of Heat and Mass Transfer >Pore-scale modeling of coupled thermal and solutal dispersion in double diffusive-advective flows through porous media
【24h】

Pore-scale modeling of coupled thermal and solutal dispersion in double diffusive-advective flows through porous media

机译：通过多孔介质的双扩散对流中热和溶液耦合耦合的孔尺度模型

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In double diffusive-advective flows through porous media, the combined effects of fluid and solid properties, pore space geometry, and flow conditions on the transport rates and distribution of the thermal and solutal fronts can be characterized by dispersion coefficients. In this study, conjugate heat and solute transport in the process of miscible displacement through porous media is studied through pore-scale numerical simulations in 2D and 3D digital representations of the unconsolidated sandpacks. The temperature and solute concentration distributions during both viscously stable and unstable displacements are obtained by solving the point equations of flow and transport on the discretized computational domains. Next, the longitudinal components of the solute and thermal dispersion coefficients are determined by fitting the effluent profiles to the analytical solutions of the advection-diffusion equations for the transport of mass and heat, respectively. The length scales of the solutal and thermal transition zones are also measured along the principal direction of the flow and then correlated with the displacement time. In stable displacements, different dispersion regimes are identified based on the magnitude of the solutal and thermal Peclet numbers. It is observed that the onset of convective spreading is different in the 2D and 3D simulation runs. In unstable displacements, the results indicate that solutal dispersion is more affected by thermo-solutal viscous fingering compared to thermal dispersion. Moreover, as the viscosity contrast across the thermal and solutal fronts increases, the dynamics of the mixing length growth gradually changes from dispersion-dominated toward fingering-dominated. Finally, the results show that two-dimensional simulation runs may not completely characterize the dispersion-related phenomena that occurs during heat and solute transfer in a real porous medium. Therefore, it is essential to conduct three-dimensional runs to capture all the underlying mechanisms contributing to the mixing and dispersion in porous media. The outcomes of this study can pave the way for an optimal design and implementation of an efficient non-isothermal miscible displacement in porous media.
机译：在通过多孔介质的双扩散对流中，流体和固体性质，孔隙空间几何形状以及流动条件对热和溶质锋面运移率和分布的综合影响可以用弥散系数来表征。在这项研究中，通过在未固结沙包的2D和3D数字表示中进行孔隙尺度数值模拟，研究了在多孔介质中混溶驱替过程中的共轭热和溶质运移。通过求解离散化计算域上的流动和输运的点方程，可以得出粘性稳定和不稳定位移过程中的温度和溶质浓度分布。接下来，通过将流出曲线与对流扩散方程的解析解拟合来确定溶质和热扩散系数的纵向分量，以分别传输质量和热量。沿流动的主方向还测量了溶液过渡区和热过渡区的长度尺度，然后将其与位移时间相关联。在稳定的位移中，根据溶解的和热的Peclet数的大小确定不同的分散状态。可以观察到，在2D和3D模拟运行中，对流扩散的开始是不同的。在不稳定的位移中，结果表明，与热分散相比，热固溶粘性指法对溶质分散的影响更大。此外，随着热和溶解前沿的粘度反差的增加，混合长度增长的动力学逐渐从分散为主变为指状为主。最后，结果表明，二维模拟运行可能无法完全表征真实多孔介质中热和溶质传递过程中发生的与分散相关的现象。因此，必须进行三维运行以捕获有助于在多孔介质中混合和分散的所有潜在机理。这项研究的结果可以为在多孔介质中有效设计和实现有效的非等温混溶驱替铺平道路。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号