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Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
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Reorientation of elongated particles at density interfaces.
A Doostmohammadi1, A M Ardekani2
1Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 15, 2014
Summary
Settling elongated particles align their long axis with the flow direction when encountering density interfaces, a behavior distinct from homogeneous fluids. This reorientation is driven by stratification effects counteracting fluid inertia.
Area of Science:
- Fluid dynamics
- Geophysical science
- Particle transport
Background:
- Density interfaces, or pycnoclines, are common in aquatic environments.
- These interfaces influence the transport of nutrients and the settling rates of particles.
Purpose of the Study:
- To investigate the settling dynamics of elongated particles through density interfaces.
- To understand the role of stratification on particle reorientation.
Main Methods:
- Direct numerical simulations of an elongated particle settling through a density interface.
- Analysis of particle orientation and settling behavior under varying stratification conditions.
Main Results:
- Elongated particles reorient their long axis parallel to the settling direction when passing through a density interface.
- Stratification effects generate turning couples that oppose fluid inertia-induced torques.
- Particle reorientation occurs in both sharp and linear density stratifications, regardless of initial orientation.
Conclusions:
- Density interfaces significantly alter the settling dynamics of elongated particles.
- Stratification plays a crucial role in particle reorientation, impacting nutrient and particle transport in aquatic systems.
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