Experiments and Simulations of Laminar Forced Convection With Water–Alumina Nanofluids in Circular Tubes

This work reports fundamental experimental-theoretical research related to heat transfer enhancement in laminar channel flow with nanofluids, which are essentially modifications of the base fluid with the dispersion of metal oxide nanoparticles. The nanofluids were synthesized by the two steps approach, using a dispersant and an ultrasound probe or a ball mill for the alumina nanoparticles dispersion within the aqueous media. The theoretical work was performed by making use of mixed symbolic-numerical computation Mathematica 7.0 platform and a hybrid numerical-analytical methodology (Generalized Integral Transform Technique - GITT) in accurately handling the governing partial differential equations for the heat and fluid flow problem formulation with temperature dependency in all the thermophysical properties. Experimental work was also undertaken based on a thermohydraulic circuit built for this purpose, and sample results are presented to verify the proposed model. The aim is to confirm that both the proposed model and available correlations previously established for regular fluids provide an adequate prevision of the heat transfer enhancement observed in laminar forced convection with such nanofluids and within the experimented Reynolds number range.