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Hydrodynamic fingering instability induced by a precipitation reaction
1Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan and Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555, Japan.
Physical Review Letters
|July 26, 2014
Summary
Precipitation reactions in fluid mixtures can cause hydrodynamic instability due to reduced permeability. This study shows how reaction-diffusion-convection models explain observed finger-like patterns in porous media.
Area of Science:
- Fluid dynamics
- Chemical reactions
- Materials science
Background:
- Precipitation reactions can alter fluid properties.
- Hydrodynamic instabilities arise from gradients in fluid properties.
Purpose of the Study:
- To experimentally demonstrate and model hydrodynamic instability triggered by precipitation.
- To investigate the influence of reactant displacement order on pattern formation.
Main Methods:
- Experiments in porous media and Hele-Shaw cells.
- Mathematical modeling of mobility profiles.
- Nonlinear simulations of reaction-diffusion-convection models.
Main Results:
- Precipitation at a miscible interface causes hydrodynamic instability.
- Finger-like precipitation patterns form, dependent on reactant order.
- Instability originates from localized permeability decrease and mobility gradients.
Conclusions:
- Localized precipitation drives hydrodynamic instability via mobility reduction.
- Asymmetric fingering patterns can result from reactant diffusivity differences.
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