A new thermal conductivity model for nanofluids

被引:883
作者
Koo, J [1 ]
Kleinstreuer, C [1 ]
机构
[1] N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA
关键词
nanofluids; effective thermal conductivity; apparent thermal conductivity; Brownian motion; interparticle potential; modeling and simulation;
D O I
10.1007/s11051-004-3170-5
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
In a quiescent suspension, nanoparticles move randomly and thereby carry relatively large volumes of surrounding liquid with them. This micro-scale interaction may occur between hot and cold regions, resulting in a lower local temperature gradient for a given heat flux compared with the pure liquid case. Thus, as a result of Brownian motion, the effective thermal conductivity, k(eff), which is composed of the particles' conventional static part and the Brownian motion part, increases to result in a lower temperature gradient for a given heat flux. To capture these transport phenomena, a new thermal conductivity model for nanofluids has been developed, which takes the effects of particle size, particle volume fraction and temperature dependence as well as properties of base liquid and particle phase into consideration by considering surrounding liquid traveling with randomly moving nanoparticles. The strong dependence of the effective thermal conductivity on temperature and material properties of both particle and carrier fluid was attributed to the long impact range of the interparticle potential, which influences the particle motion. In the new model, the impact of Brownian motion is more effective at higher temperatures, as also observed experimentally. Specifically, the new model was tested with simple thermal conduction cases, and demonstrated that for a given heat flux, the temperature gradient changes significantly due to a variable thermal conductivity which mainly depends on particle volume fraction, particle size, particle material and temperature. To improve the accuracy and versatility of the k(eff) model, more experimental data sets are needed.
引用
收藏
页码:577 / 588
页数:12
相关论文
共 20 条
[1]  
[Anonymous], 1992, INTERMOLECULAR SURFA
[2]   Brownian dynamics simulation to determine the effective thermal conductivity of nanofluids [J].
Bhattacharya, P ;
Saha, SK ;
Yadav, A ;
Phelan, PE ;
Prasher, RS .
JOURNAL OF APPLIED PHYSICS, 2004, 95 (11) :6492-6494
[3]  
Chapman S, 1951, Mathematical theory of nonuniform gases, Vsecond
[4]   Anomalous thermal conductivity enhancement in nanotube suspensions [J].
Choi, SUS ;
Zhang, ZG ;
Yu, W ;
Lockwood, FE ;
Grulke, EA .
APPLIED PHYSICS LETTERS, 2001, 79 (14) :2252-2254
[5]   Temperature dependence of thermal conductivity enhancement for nanofluids [J].
Das, SK ;
Putra, N ;
Thiesen, P ;
Roetzel, W .
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 2003, 125 (04) :567-574
[6]  
Deen W.M., 2012, Analysis of Transport Phenomena
[7]   Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles [J].
Eastman, JA ;
Choi, SUS ;
Li, S ;
Yu, W ;
Thompson, LJ .
APPLIED PHYSICS LETTERS, 2001, 78 (06) :718-720
[8]   THERMAL CONDUCTIVITY OF HETEROGENEOUS 2-COMPONENT SYSTEMS [J].
HAMILTON, RL ;
CROSSER, OK .
INDUSTRIAL & ENGINEERING CHEMISTRY FUNDAMENTALS, 1962, 1 (03) :187-&
[9]   Role of Brownian motion in the enhanced thermal conductivity of nanofluids [J].
Jang, SP ;
Choi, SUS .
APPLIED PHYSICS LETTERS, 2004, 84 (21) :4316-4318
[10]   Mechanisms of heat flow in suspensions of nano-sized particles (nanofluids) [J].
Keblinski, P ;
Phillpot, SR ;
Choi, SUS ;
Eastman, JA .
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 2002, 45 (04) :855-863