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Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy
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Integral representation of channel flow with interacting particles.
Itzhak Fouxon1,2, Zhouyang Ge3, Luca Brandt3
1Department of Chemical Engineering, Technion, Haifa 32000, Israel.
Physical Review. E
|January 20, 2018
Summary
Low-Reynolds-number flow in channels with suspended particles shows particles separating into singlets and pairs. This study models particle interactions and predicts their collective behavior in dilute suspensions.
Area of Science:
- Fluid dynamics
- Multiphase flow
- Computational physics
Background:
- Understanding particle behavior in channel flow is crucial for various industrial and biological processes.
- Low-Reynolds-number flows simplify fluid dynamics, allowing for detailed analysis of particle interactions.
Purpose of the Study:
- To develop a boundary integral representation for low-Reynolds-number flow with arbitrary particles.
- To analyze hydrodynamic interactions and predict the emergent collective behavior of suspended particles.
Main Methods:
- Constructed a boundary integral representation for the flow.
- Derived a multipole expansion of the flow, approximating it as dipolar.
- Developed an equation of motion for hydrodynamic interactions between particles.
Main Results:
- Lubrication theory is valid away from particles when distances exceed channel height.
- Derived the particle dipole moment as a weighted integral of surface stress and flow.
- Analytically and numerically derived the 'pair exchange' phenomenon for aligned spheres.
- Observed particle separation from stable pairs for nonaligned particles.
Conclusions:
- Particles in a dilute, homogeneous suspension eventually separate into singlets and pairs.
- The derived model accurately predicts particle interactions and collective dynamics.
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