期刊
APPLIED THERMAL ENGINEERING
卷 73, 期 1, 页码 296-306出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.applthermaleng.2014.07.060
关键词
SiO2 nanofluid; Twisted tape; Numerical model; van Driest eddy diffusivity equation; Heat transfer coefficient; Friction factor
资金
- Universiti Malaysia Pahang [GRS100354, RDU130391]
A numerical model has been developed for turbulent flow of nanofluids in a tube with twisted tape inserts. The model is based on the assumption that van Driest eddy diffusivity equation can be applied by considering the coefficient and the Prandtl index in momentum and heat respectively as a variable. The results from the numerical analysis are compared with experiments undertaken with SiO2/water nanofluid for a wide range of Reynolds number, Re. Generalized equation for the estimation of nanofluid friction factor and Nusselt number is proposed with the experimental data for twisted tapes. The coefficient and the Prandtl index in the eddy diffusivity equation of momentum and heat is obtained from the numerical values as a function of Reynolds number, concentration and twist ratio. An enhancement of 94.1% in heat transfer coefficient and 160% higher friction factor at Re = 19,046 is observed at a twist ratio of five with 3.0% volumetric concentration when compared to flow of water in a tube. A good agreement with the limited experimental data of other investigators is observed with Al2O3 and Fe3O4 nanofluids indicating the validity of the numerical model for use with twisted tape inserts. (C) 2014 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据