This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The present work uses the continuum description of nanofluid flow to study the flow, heat and
mass transfer in the entrance and developing region of channels or tubes, where the viscous and heat
conduction layers are thin and the heat transfer is much more intense than fully developed flow. Instead of
supplementing the formulation with thermodynamic properties based on mixture calculations, use is made of
recent molecular dynamical computations of such properties, specifically, the density and heat capacity of
gold-water nanofluids. The more general formulation results, within the Rayleigh-Stokes (plug flow)
approximation and perturbation for small volume fraction, show that the nanofluid density-heat capacity has
an enormous effect in the inertia mechanism in causing the nanofluid temperature profile to steepen. The
nanofluid thermal conductivity though has an explicit enhancement of the surface heat transfer rate has the
almost hidden effect of stretching the nanofluid temperature profile thus giving the opposite effect of
enhancement