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.In this paper an experimental and numerical study to investigate the convective heat transfer
characteristics of fully developed turbulent flow of a water–Al2O3 nanofluid in a circular tube is presented.
The numerical simulations are accomplished on the experimental test section configuration. In the analysis,
the fluid flow and the thermal field are assumed axial-symmetric, two-dimensional and steady state. The
single-phase model is employed to model the nanofluid mixture and k-ε model is used to describe the
turbulent fluid flow. Experimental and numerical results are carried out for different volumetric flow rates
and nanoparticles concentration values. Heat transfer convective coefficients as a function of flow rates and
Reynolds numbers are presented. The results indicate that the heat transfer coefficients increase for all
nanofluids concentrations compared to pure water at increasing volumetric flow rate. Heat transfer
coefficient increases are observed at assigned volumetric flow rate for nanofluid mixture with higher
concentrations whereas Nusselt numbers present lower values than the ones for pure water
