Comparing Mathematical Models to Calculate the Thermal Conductivity of Nanofluids


Nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or nano_ metallic nanoparticles with a typical size of less than 100 nm in the conventional heat transfer fluids.In order to study the heat transfer behavior of the nanofluids, precise values of thermal and physical properties such as thermal conductivity of the nanofluids is required . There are a few well_known correlations for predicting the thermal conductivity of nanofluids which are often cited by researchers to calculate the convective heat transfer behaviors of the nanofluids. Each researcher has used different models of the thermal conductivity in their works. This article aims to summarize the various models for predicting the thermal conductivity of nanofluids which have been commonly cited by a number of researchers and use them to calculate the experimental and theoretical convective heat transfer coefficient of nanofluid flowing in heat exchangers.Results show that difference between calculated thermal conductivity from models increases with increasing the volume concentrations and also slightly increases with thermal conductivity of nanoparticles. Experimental results show that aggregation of nanoparticles have significant effect on the predicted values of thermal conductivity of nanofluids.

Keywords: Nano fluids; Thermal conductivity; Nanoparticles; Convective heat transfer coefficient; Aggregation

PDF Format of Article


  • Ali,A.,vafai,k.,& khaled,A.R.A.(2004).Analysis of heat and mass transfer between air and falling film in a cross flow configuration. Int.J.Heat and Mass Ttransfer.47,743_755.
  • Ali,A.,& Vafai,K.(2004).An investigation of heat and mass transfer between air and desiccant film in a inclined parallel and counter flow channels. Int.J.Heat and Mass Transfer.47,1754_1760.
  • Batchelor,G.K.(1977),The effect of Brownian motion on the bulk stress in a suspension of spherical particles.J.Fluid Mech.83,97_117.
  • Chein,R.,& Chuang,J.(2007).Experimental microchannel heat sink performance studies using nanofluids. Int.J.Thermal Science.46(1),55_66.
  • Daungthongsuk,W.,&Wong wises,S.(2007).A critical review of convective heat transfer of nanofluids.Renew.Sustain.Energr Rev.11,797_817.
  • Estman,J.A.,Phillpot,S.R.,Choi,S.U.S.&Keblinski,P.K.(2004).Thermal transport in nanofluids.Annual Review Of Material Research.34,219_246.
  • Hamilton,R.L.,&Crosser,o.k.(1962).Thermal conductivity of heterogeneous two_component systems.I & EC Fundamentals.1(3),1878_191.
  • Heris,S.Z.,Etemad.S.G.,&Esfahany,M.N.(2006).Experimental investigation of oxide nanofluids laminar flow convective heat transfer.Int Commun Heat Fluid Flow. 33,529_535.
  • Heris,S.Z.Esfahani,M.N.,&Etemad,S.G(2007).Experimental investigation of convective heat transfer of / water nanofluid in circular tube .Int.J.Heat Fluid Flow.28(2),203_210.
  • Mansour,R.D.,Galsnis,N.,&Ngugen,.C.T.(2007).Effect of uncertainties in physical properties on forced convection heat transfer with nanofluids.Appl.Therm.Eng.27(11),240_249.
  • Maxwell,J.C.(1904).A treatise on electricity and magnetism,third ed.,Clarendon press,Oxford.
  • Murshed,S.M.S,Leong,K.C.,&Yang,C.(2005).Enhanced thermal conductivity of _ water nanofluids.Int.J.Therm.Sci.44,367_373.
  • Pak,B.C.,&Choi,Y.I.(1998).Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles.Exp.Heat Transfer.11,151_170.
  • Roy,G.Nguyen,C.T.,&Lajoie,P.R.(2004).Numerical investigation of laminar flow and heat transfer in a radial flow cooling system with the use of nanofluids.Superlattices Microstruct.35,497_511.
  • Trisaksri,V.,&Wongwises,S.(2007).Critical review of heat transfer characteristics of the nanofluids. Renew.Sustain.Energy Rev.11(3),512_523.
  • Wang,X.,Xu,X.,&Choi,S.U.S.(1999).Thermal conductivity of nanoparticles_fluid          mixture.J.Thermophys.Heat Transfer.13(4),474_480.
  • Xuan , Y.&Li,Q.(2000).Heat transfer enhancement of nanofluids,Int.J.Heat Fluid Flow.21,58.
  • Xuan,Y.&Li,Q.(2003).Investigation of convective heat transfer and flow features of nannofluids.ASME.J.Het Transfer.125,151_155.
  • Xuan,Y.,Li,Q.,&Hu,W.(2003).Aggregation structure and thermal conductivity of nanofluids. AICHEJ.49,1038_1043.