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Title: Taylor dispersion in high aspect ratio tubes of nearly rectangular cross section.


No abstract prepared.

Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
OSTI Identifier:
Report Number(s):
TRN: US200616%%1014
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Proposed for publication in the Journal of Fluid Mechanics.
Country of Publication:
United States

Citation Formats

Romero, Louis Anthony, and Parks, Michael L. Taylor dispersion in high aspect ratio tubes of nearly rectangular cross section.. United States: N. p., 2005. Web.
Romero, Louis Anthony, & Parks, Michael L. Taylor dispersion in high aspect ratio tubes of nearly rectangular cross section.. United States.
Romero, Louis Anthony, and Parks, Michael L. Tue . "Taylor dispersion in high aspect ratio tubes of nearly rectangular cross section.". United States. doi:.
title = {Taylor dispersion in high aspect ratio tubes of nearly rectangular cross section.},
author = {Romero, Louis Anthony and Parks, Michael L.},
abstractNote = {No abstract prepared.},
doi = {},
journal = {Proposed for publication in the Journal of Fluid Mechanics.},
number = ,
volume = ,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
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  • A numerical calculation has been performed for the simultaneously developing laminar velocity and temperature fields in the entrance region of an isothermal rectangular duct rotating about an axis perpendicular to the duct axis. The present paper particularly addresses the effect of the aspect ratio of the rectangular duct. The vorticity-velocity method with the power law scheme is employed to solve the governing equations for the flow and heat transfer. It is seen that pairs of counterrotating vortices appear in the cross section of the duct. The number of vortex pairs depends on the aspect ratio of the duct. Under somemore » circumstances, the number of vortex pairs with axial position. The numerically calculated stability boundary points for small aspect ratio show excellent agreement with the neutral stability curve, which was obtained by linear stability analysis. Friction factor and Nusselt number are presented as functions of axial position, and it is seen that they are strongly affected by the vortices. Comparisons with existing theoretical and experimental results are also presented.« less
  • An analytic solution is obtained for free-boundary, high-beta equilibria in large aspect ratio tokamaks with a nearly circular plasma boundary. In the absence of surface currents at the plasma-vacuum interface, the free-boundary equilibrium solution introduces constraints arising from the need to couple to an external vacuum field which is physically realizable with a reasonable set of external field coils. This places a strong constraint on the pressure profiles that are consistent with a given boundary shape at high {epsilon}{beta}{sub p}. The equilibrium solution also provides information on the flux surface topology. The plasma is bounded by a separatrix. Increasing themore » plasma pressure at fixed total current causes the plasma aperture to decrease in a manner that is described. {copyright} {ital 1997 American Institute of Physics.}« less
  • Natural convection in rectangular cavities with the vertical endwalls differentially heated about the temperature of maximum density of water was studied in the laboratory. In order to control heat losses, the experiments were conducted in a large cold room with the air temperature maintained at 4C. The Rayleigh number was varied over the range 10{sup 5} to 10{sup 8} and the aspect ratio over the range 0.1 to 0.5. The flow field consisted of a double cellular circulation, and the observed temperature field, flow field, and heat transfer rates were compared with analytical predictions in the diffusive regime. The experimentsmore » demonstrated that the interior inking flow was unstable for Ra > 10{sup 7}.« less