Remarks on Constitutive Modeling of Nanofluids

We discuss briefly the constitutive modeling of the stress tensor for nanofluids. In particular, we look at the viscosity of nanofluids containing multiwalled carbon nanotubes (MWCNTs) stabilized by cationic chitosan. MWCNTs can be used either to enhance or reduce the fluid base viscosity depending on their weight fractions. By assuming that MWCNT nanofluids behave as generalized second-grade fluid where the viscosity coefficient depends upon the rate of deformation, a theoretical model is developed. A simplified version of this model, similar to the traditional power-law model, is used in this study. It is observed that the theoretical results agree well with the experimental data.