Numerical analysis on forced convection enhancement in an annulus using porous ribs and nanoparticle addition to base fluid

来源期刊:中南大学学报(英文版)2019年第5期

论文作者:Majid Siavashi Hamid Reza TALESH BAHRAMI Ehsan AMINIAN Hamid SAFFARI

文章页码:1089 - 1098

Key words:nanofluid; porous media; annulus; heat transfer enhancement; internal flow

Abstract: Miniaturization of electronic equipment has forced researchers to devise more effective methods for dissipating the generated heat in these devices. In this study, two methods, including porous media inserting and adding nanoparticles to the base fluid, are used to improve heat transfer in an annulus heated on both walls. To study porous media insert, porous ribs are used on the outer and inner walls independently. The results show that when porous ribs are placed on the outer wall, although the heat transfer enhances, the pressure drop increment is so considerable that performance number (the ratio of heat transfer enhancement pressure increment, PN) is less than unity for all porous rib heights and porous media permeabilities that are studied. On the other hand, the PN of cases where porous ribs were placed on the inner wall depends on the Darcy number (Da). For example, for ribs with Da=0.1 and Da=0.0001, the maximum performance number, PN=4, occurs at the porous ribs height to hydraulic diameter ratios H/Dh=1 and H/Dh=0.25. Under these conditions, heat transfer is enhanced by two orders of magnitude. It is found that adding 5% nanoparticles to the base fluid in the two aforementioned cases improves the Nusselt number and PN by 10%–40%.

Cite this article as: Majid SIAVASHI, Hamid Reza TALESH BAHRAMI, Ehsan AMINIAN, Hamid SAFFARI. Numerical analysis on forced convection enhancement in an annulus using porous ribs and nanoparticle addition to base fluid [J]. Journal of Central South University, 2019, 26(5): 1089–1098. DOI: https://doi.org/10.1007/s11771-019- 4073-z.

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号