ISSN Online: 2377-424X
International Heat Transfer Conference 3
NATURAL CONVECTION IN HORIZONTAL CYLINDRICAL ANNULI
Sinopsis
By aid of a Mach-Zehnder interferometer
the temperature fields of a concentric
horizontal annulus, filled with
atmospheric air, were made visible.From
these fields the local and the mean
Nusselt numbers for the inner cylinder
were evaluated in a region of the Grashof
number Grδ from 320 to 716 000
(δ is the gap width).The flow lines were
observed by cigarette smoke using the
method of normal incident light. Three
different regimes of convective motion
were found.
a two dimensional pseudo-conductive regime a transition regime with a three dimensional motion and a regime, having a fully developed two dimensional laminar convective flow. The local and the mean Nusselt numbers Nuδ as a function of the Grashof numbers Grδ and the relative gap width δ/di are in good agreement with the results of other investigators. These results however extend the region of study.
a two dimensional pseudo-conductive regime a transition regime with a three dimensional motion and a regime, having a fully developed two dimensional laminar convective flow. The local and the mean Nusselt numbers Nuδ as a function of the Grashof numbers Grδ and the relative gap width δ/di are in good agreement with the results of other investigators. These results however extend the region of study.