LAMINAR NATURAL CONVECTION ON A VERTICAL SURFACE WITH ADIABATIC DISCRETE ROUGHNESS.
American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD
Date of Presentation
Numerical predictions of natural convection in a differentially heated rectangular enclosure with adiabatic roughness elements attached to its heated wall are reported. The objective is to document the effects of these roughness on the heat transfer and fluid flow in two-dimensional enclosures heated and cooled from the sides. Each roughness element consisted of a horizontal cylinder of rectangular cross section whose height was on the order of the boundary layer thickness. Numerical results of heat transfer and velocity components were obtained by a finite-difference algorithm. The results showed that the existence of nonconducting roughness causes the initiation of a secondary boundary layer above the roughness. This would seem to cause an enhancement of the local heat transfer compared with the case of smooth-wall enclosure. In spite of this increase in the local heat transfer above the element, the average heat transfer is less than that for the smooth-wall enclosure.
LAMINAR NATURAL CONVECTION ON A VERTICAL SURFACE WITH ADIABATIC DISCRETE ROUGHNESS..
Paper presented at American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD.