...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Transport in Porous Media >Computational Analysis of Interfacial Dynamics in Angled Hele-Shaw Cells: Instability Regimes
【24h】

Computational Analysis of Interfacial Dynamics in Angled Hele-Shaw Cells: Instability Regimes

机译：有角度的Hele-Shaw细胞界面动力学的计算分析：不稳定状态

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

We present a theoretical and numerical study on the (in)stability of the interface between two immiscible liquids, i.e., viscous fingering, in angled Hele-Shaw cells across a range of capillary numbers (Ca). We consider two types of angled Hele-Shaw cells: diverging cells with a positive depth gradient and converging cells with a negative depth gradient, and compare those against parallel cells without a depth gradient. A modified linear stability analysis is employed to derive an expression for the growth rate of perturbations on the interface and for the critical capillary number (Cac) for such tapered Hele-Shaw cells with small gap gradients. Based on this new expression for Cac, a three-regime theory is formulated to describe the interface (in)stability: (i) in Regime I, the growth rate is always negative, thus the interface is stable; (ii) in Regime II, the growth rate remains zero (parallel cells), changes from negative to positive (converging cells), or from positive to negative (diverging cells), thus the interface (in)stability possibly changes type at some location in the cell; (iii) in Regime III, the growth rate is always positive, thus the interface is unstable. We conduct three-dimensional direct numerical simulations of the full Navier-Stokes equations, using a phase field method to enforce surface tension at the interface, to verify the theory and explore the effect of depth gradient on the interface (in)stability. We demonstrate that the depth gradient has only a slight influence in Regime I, and its effect is most pronounced in Regime III. Finally, we provide a critical discussion of the stability diagram derived from theoretical considerations versus the one obtained from direct numerical simulations.
机译：我们提供了在一定角度的Hele-Shaw细胞中跨一定范围的毛细管数（Ca）的两种不混溶液体之间的界面（不稳定性）的理论和数值研究，即粘性指法。我们考虑两种类型的成角度的Hele-Shaw单元：具有正深度梯度的发散单元和具有负深度梯度的会聚单元，并将它们与没有深度梯度的平行单元进行比较。修改后的线性稳定性分析用于得出这种扰动在界面上的增长率以及对于这种具有小间隙梯度的渐缩Hele-Shaw细胞的临界毛细管数（Cac）的表达式。基于Cac的这个新表达式，提出了一种三区域理论来描述界面的（不稳定性）：（i）在区域I中，增长率始终为负，因此界面稳定。 （ii）在制度II中，增长率保持为零（平行细胞），从负变为正（会聚细胞），或从正变为负（发散细胞），因此界面（不稳定性）可能在某些位置改变类型在牢房里（iii）在制度III中，增长率始终为正，因此界面不稳定。我们使用相场方法在界面处施加表面张力，对整个Navier-Stokes方程进行了直接的三维模拟，以验证理论并探讨深度梯度对界面（不稳定性）的影响。我们证明了深度梯度对区域I的影响很小，而对区域III的影响最为明显。最后，我们对稳定性图进行了严格的讨论，该稳定性图是从理论考虑中得出的，而不是从直接数值模拟中得出的。

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