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Interface and contact line motion in a two phase fluid under shear flow
1Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Physical Review Letters
|September 6, 2000
Summary
Steady shear flow in two-phase fluids causes interfacial slip due to order parameter relaxation. This phenomenon is characterized by a specific length scale and depends on fluid layer width and capillary number.
Area of Science:
- Fluid dynamics
- Soft matter physics
- Interfacial phenomena
Background:
- Understanding two-phase fluid behavior under shear is crucial for various applications.
- Interfacial slip and its underlying mechanisms remain an active area of research.
Purpose of the Study:
- To investigate the steady-state interfacial configuration of two-phase fluids subjected to steady shear.
- To analyze the role of dissipative relaxation of the order parameter in generating interfacial slip.
Main Methods:
- Employing a coarse-grained description to model the fluid system.
- Analyzing the characteristic length scale of order parameter relaxation: l(0) = sqrt[xiD/V0].
- Deriving scaling laws for the steady-state interfacial configuration.
Main Results:
- Dissipative relaxation of the order parameter induces interfacial slip at the contact line, irrespective of no-slip velocity conditions.
- The relaxation process is confined to a characteristic length scale, l(0).
- The steady-state configuration scales with the ratio l(0)/L (fluid layer width) for passive interfaces and includes the capillary number for active interfaces.
Conclusions:
- Interfacial slip in sheared two-phase fluids is a direct consequence of order parameter dynamics.
- The identified scaling laws provide a framework for predicting interfacial behavior across different system parameters.
- This study offers insights into the fundamental physics governing complex fluid interfaces.