Heat transfer enhancement using Al2O3-EG/W(60/40 vol%) in multiple-pipe heat exchanger

Abstract

The heat transfer enhancement in a D-shaped heat exchanger using nanofluid is analyzed using a modern numerical method. The double-MRT lattice Boltzmann method is utilized to simulate the fluid flow and heat transfer. On the experimental phase, the thermal conductivity and viscosity of Al2O3-EG/W(60/40 vol%) are measured using experiments with modern devices. Some correlations based on experimental data are developed as a function of temperature for different nanoparticle concentrations. These temperature/nanoparticle concentration-based correlations are used in the numerical simulations to enhance the accuracy of results. In the present investigation, the impacts of Rayleigh number (103 < Ra < 106), nanoparticle concentration (0, 0.2, 0.4, 0.6, 0.8 and 1 vol%) and different arrangements of internal pipes on the streamlines, isotherm patterns, local/average heat transfer rate, local/average entropy generation and heatlines are studied comprehensively.