Nanofluids natural convection heat transfer in horizontal annulus

Journal Article

Zeitoun, O. . 2009

• Magazine \ Newspaper: Int. J. Nanoparticles
• Volume Number: 2
• Pages: Nos. 1/2/3/4/5/6

Publication Abstract

Effect of nanoparticles on natural convection in horizontal cylindrical annuli was investigated numerically using finite volume technique together with SIMPLE algorithm. Annulus geometric configurations of Do/Di = 2 and 1.25 were investigated. The nanofluid used in current simulation is aluminum oxide (Al2O3) nanoparticles in water as base fluid. Laminar conditions up to Rayleigh number R of 109 were investigated 0, 1 and 4% nanoparticle concentration. The data of heat transfer, represented by effective thermal conductivity ratio were presented versus Rayleigh number Ra. The results indicated that nanoparticles can increase heat transfer in conduction dominated regime while decrease heat transfer in convection dominated regime.