Abstract
A numerical scheme based on the distributed Lagrange multiplier method (DLM) is used to study the motion of nano sized particles of dielectric suspensions subjected to uniform and nonuniform electric fields. Particles are subjected to both electrostatic and hydrodynamic forces, as well as Brownian motion. The results of the simulations presented in this paper show that in the case of uniform electric fields the evolution of the particle structures depends on the ratio of electrostatic particle-particle interactions and Brownian forces. For solids fraction of the order 0.01, when this ratio is of the order of a hundred or more particles form stable chains and columns whereas when this ratio is of the order ten the particles are distributed in a random manner. For the non uniform electric field cases considered in this paper, the relative magnitude of Brownian forces is in the range such that it does not influence the eventual collection of particles by dielectrophoresis and the particular locations where the particles are collected. However. Brownian motion is observed to influence the transient particle trajectories. The deviation of the particle trajectories compared to those determined by the electrostatic and hydrodynamic forces alone is characterized by the ratio of Brownian and dielectrophoretic forces.
Original language | English (US) |
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Article number | IMECE2004-61529 |
Pages (from-to) | 85-92 |
Number of pages | 8 |
Journal | American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED |
Volume | 260 |
DOIs | |
State | Published - 2004 |
Event | 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE 2004 - Anaheim, CA, United States Duration: Nov 13 2004 → Nov 19 2004 |
All Science Journal Classification (ASJC) codes
- General Engineering
Keywords
- Brownian force
- Dielectrophoresis
- Distributed Lagrange multiplier method
- Nanoparticles