Natural convection in horizontal cylindrical annuli

Journal Article

D., Alshahrani, . 2005

• Magazine \ Newspaper: Alexandria Engineering Journal
• Issue Number: 6
• Volume Number: 44

Publication Abstract

Natural convection in horizontal cylindrical annuli was investigated numerically using finite
element technique together with SIMPLER algorithm. Annulus geometric configurations of
Do/Di = 2, 3, 4 and 5 were investigated. Laminar conditions up to Rayleigh number Rai of 105
 were investigated. Flow fields represented by stream lines, velocity vectors and isothermal
lines were presented for various conditions. The data of heat transfer, represented by Nusselt
number Nui and effective thermal conductivity ratio ke/k were presented versus Rayleigh
number Rai. The data of effective thermal conductivity ratio ke/k were presented versus a new
modified Rayleigh number Ram. Three regimes of heat transfer were observed; conduction
dominated, transition and convection dominated regimes. The data of heat transfer,
represented by the effective thermal conductivity ratio ke/k were correlated and comparison
with existed experimental data indicates the accuracy of new correlations.