Atomistic fluid flow transitions
inside carbon nanotubes
Oak Ridge National Laboratory
This is an abstract
for a poster to be presented at the
Foresight Conference on Molecular Nanotechnology.
There will be a link from here to the full article when it is
available on the web.
The physics of fluid flow within volumes at the nanometer size
scale is not well understood. Preliminary evidence suggests a
possible critical transition in flows through carbon nanotubes
which could take the form of a bifurcation of the flow rate as a
function of pressure gradient. Such a phenomenon could be
considered to be the atomistic equivalent of a transition from
laminar to turbulent flow seen in "continuous" fluids.
Fluid flow transitions at the nanometer size scale would have a
profound impact on the design of nano-fluidic devices and
structures. Simple heuristic models for these phenomena could
help accelerate and direct the design of devices and structures
whose operation depends on nanometer scale flow transitions.
Results of molecular dynamics simulations of the flow of
hydrogen inside carbon nanotubes are reported. The nanotube is
clamped at the ends and hydrogen molecules recycled as they reach
the end of the nanotube. To simulate a pressure gradient, the
axial velocities of the hydrogen molecules are set to a fixed
value as they recycle. In continuous fluid dynamics, the
laminar/turbulent transition can be modelled as the solution to
several possible sets of differential equations with bifurcating
solutions above a critical velocity. The results of similar
models applied to the above simulations are reported.
Research sponsored by the Division of Materials Sciences,
Office of Basic Energy Sciences, U.S. Department of Energy under
contract DE-AC05-96OR22464 with Lockheed-Martin Energy Research
Robert E. Tuzun, Oak Ridge National Laboratory, Fusion Energy
P. O. Box 2008, Oak Ridge, TN 37831-6197
ph: 423-574-4974, fax: 423-576-5235, email: email@example.com