Effect of particle migration on heat transfer in suspensions of nanoparticles flowing through minichannels

Recent work has shown that suspensions of highly thermally conducting nanoparticles with a size considerably smaller than 100 nm have great potential as a high-energy carrier for small channel systems. However, it is also known that particles in a suspension under certain conditions may migrate. Thi...

Full description

Saved in:
Bibliographic Details
Published in:Microfluidics and nanofluidics 2005-05, Vol.1 (2), p.183-189
Main Authors: Wen, Dongsheng, Ding, Yulong
Format: Article
Language:English
Subjects:
Atoms & subatomic particles
Energy equation
Heat transfer
Laminar flow
Migration
Studies
Thermal conductivity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Recent work has shown that suspensions of highly thermally conducting nanoparticles with a size considerably smaller than 100 nm have great potential as a high-energy carrier for small channel systems. However, it is also known that particles in a suspension under certain conditions may migrate. This indicates that the efficiency of heat transfer in the small channels may not be as superior as expected, which bears significance to the system design and operation. This work aims at addressing this issue by examining the effect of particle migration on heat transfer under a fully developed laminar flow regime in small channels. This involves the development of both flow and heat transfer models, and a numerical solution to the models. The flow model takes into account the effects of the shear-induced and viscosity-gradient-induced particle migration, as well as self-diffusion due to Brownian motion, which is coupled with an energy equation. The results suggest a significant non-uniformity in particle concentration and, hence, thermal conductivity over the tube cross-section due to particle migration, particularly for large particles at high concentrations. Compared with the constant thermal conductivity assumption, the non-uniform distribution due to particle migration leads to a higher Nusselt number, which depends on the Peclet number and the mean particle concentration. Further improvement of the model is needed to take into account other factors such as entrance effects, as well as the dynamics of particles and particle-wall interactions.[PUBLICATION ABSTRACT]
ISSN:1613-4982
1613-4990
DOI:10.1007/s10404-004-0027-2