Drag force on a particle straddling a fluid interface: Influence of interfacial deformations
J -C Loudet1,2, M Qiu3, J Hemauer3
1University of Bordeaux, CNRS, Centre de Recherche Paul Pascal (UMR 5031), F-33600, Pessac, France. jean-christophe.loudet@u-bordeaux.fr.
The European Physical Journal. E, Soft Matter
|February 16, 2020
Summary
Particle interfacial deformations significantly affect fluid drag. Surprisingly, smaller interfacial distortions can lead to lower drag forces, challenging the assumption that larger distortions always increase resistance.
Area of Science:
- Fluid dynamics
- Interfacial phenomena
- Computational physics
Background:
- Particles at fluid interfaces experience drag forces influenced by interface shape.
- Interfacial deformations, driven by particle buoyancy, create curved menisci.
- Understanding this interaction is crucial for multiphase flow applications.
Purpose of the Study:
- To numerically investigate how interfacial deformations impact drag on particles at fluid interfaces.
- To quantify the relationship between drag coefficients and parameters like contact angle, viscosity ratio, and particle density.
Main Methods:
- Finite element simulations of two-phase flow in 2D.
- Phase-field method coupled with Navier-Stokes equations for interface and flow dynamics.
- Calculation of drag coefficients across various physical parameters.
Main Results:
- Drag force is sensitive to interfacial deformations, not solely dependent on their magnitude.
- Curved menisci due to particle buoyancy can alter drag.
- Lower drag can occur with non-flat interfaces compared to unperturbed ones for certain conditions.
Conclusions:
- Interfacial shape plays a complex role in particle drag at fluid interfaces.
- The assumption that larger distortions equate to higher drag is not universally true.
- Optimizing interfacial geometry may reduce drag in specific scenarios.
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