Linear stability of layered two-phase flows through parallel soft-gel-coated walls.
Linear stability of layered two-phase flows through parallel soft-gel-coated walls.
复制标题
层状两相流穿过平行软凝胶涂层壁的线性稳定性。
DOI：
10.1103/physreve.96.013119
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. Pushpavanam
中科院分区：
文献类型：
--
作者：
B. Dinesh;S. Pushpavanam
本文研究了通过软凝胶涂层平行壁的分层两相Poiffille流的线性稳定性。重点是确定流体和软凝胶层之间的弹性流体动力学耦合的效果上观察到的不同的不稳定性之间的流动平行板。假设流体为牛顿流体且不可压缩，而软凝胶被建模为线性粘弹性固体。长波渐近分析被用来获得的扰动的增长率的解析表达式。采用切比雪夫配点法对一般线性化方程组进行数值求解。在流动中识别出三种不同的不稳定模式：（a）液-液长波模式;（B）液-液短波模式;（c）凝胶-液短波模式。分析了软凝胶的可变形性对这三种模式的影响。从长波分析的液-液模式的稳定性地图，其中四个不同的区域被明确划定。它示出，在更粘的流体附近引入凝胶层对刚性板之间的流动中看到的这种模式具有显著的稳定效果。对于刚性板之间的流动的这种模式是稳定的参数，在粘性较低和较薄的流体附近引入凝胶层具有主要的不稳定效应。液-液短波模式是不稳定的软凝胶层的引入。确定了由软凝胶层的可变形性引起的凝胶-液体界面处的其他不稳定模式。我们表明，这些可以通过改变凝胶层的厚度来控制。洞察驱动不同的不稳定性的物理机制，获得使用能量预算分析。
The linear stability of layered two-phase Poiseuille flows through soft-gel-coated parallel walls is studied in this work. The focus is on determining the effect of the elastohydrodynamic coupling between the fluids and the soft-gel layers on the different instabilities observed in flows between parallel plates. The fluids are assumed Newtonian and incompressible, while the soft gels are modeled as linear viscoelastic solids. A long-wave asymptotic analysis is used to obtain an analytical expression for the growth rate of the disturbances. A Chebyshev collocation method is used to numerically solve the general linearized equations. Three distinct instability modes are identified in the flow: (a) a liquid-liquid long-wave mode; (b) a liquid-liquid short-wave mode; (c) a gel-liquid short-wave mode. The effect of deformability of the soft gels on these three modes is analyzed. From the long-wave analysis of the liquid-liquid mode a stability map is obtained, in which four different regions are clearly demarcated. It is shown that introducing a gel layer near the more viscous fluid has a predominantly stabilizing effect on this mode seen in flows between rigid plates. For parameters where this mode is stable for flow between rigid plates, introducing a gel layer near the less viscous and thinner fluid has a predominantly destabilizing effect. The liquid-liquid short-wave mode is destabilized by the introduction of soft-gel layers. Additional instability modes at the gel-liquid interfaces induced by the deformability of the soft-gel layers are identified. We show that these can be controlled by varying the thickness of the gel layers. Insights into the physical mechanism driving different instabilities are obtained using an energy budget analysis.
影响因子：
56.9
作者：
Unger, MA;Chou, HP;Quake, SR
通讯作者：
Quake, SR