Differential effective medium theory for thermal conductivity in nanofluids

By taking into account both physical and geometrical anisotropy of the highly conducting nanoparticle inclusions, we present differential effective medium theory to estimate the effective thermal conductivity in nanofluids. It is found that the adjustment of the nanoparticles shape is really helpful to achieve appreciable enhancement of effective thermal conductivity. Moreover, numerical results are in good agreement with the experimental ones observed in nanofluids. To one's interest, our theoretical predictions successfully show a nonlinear dependence of effective thermal conductivity on the volume fractions. (c) 2005 Elsevier B.V. All rights reserved.