Biomedical Engineering Reference
In-Depth Information
The level of enhancement observed for many different kinds of nanofluids
can hardly be explained by existing theoretical models in the literature. A
single unified theory that may explain the many-fold increase in thermal
conductivity still remains elusive. For wide-scale application, the effects of
erosion, particle settling, and agglomeration need to be studied in detail.
The agglomeration of particles in a nanofluid is aggravated by the two-step
process of producing nanofluids where powders are added to liquids. The
dispersion and suspension of nanoparticles in a fluid pose a difficult
colloidal chemistry problem, and considerable work remains to be done if
the two-step process is ever to develop into large-scale production. (The
two-step process is currently the most economical way to produce
nanofluids and has good potential for scale-up to commercial production
levels.) Better characterization of nanofluids is also important for
developing engineering designs based on the work of multiple research
groups, and fundamental theories to guide this effort should be improved.
Important features for commercialization must be addressed, including
particle settling, particle agglomeration, surface erosion, and large-scale
nanofluid production at acceptable cost.
11.6 References
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Bruggeman, D. A. G. (1935), Berechnung verschiedener physikalisher Konstanten
