Numerical Study of Heat Transfer Characteristics of Nano-fluids in Channel Containing Different Shapes of Submerged Tube

The convective heat transfer coefficient of nanofluids in a channel has been numerically studied for the laminar flow condition. The channel has been confined with inline noncircular tubes. The computational channel has aspect ratios of 10 × 0.66 cm² with five different circular and non-circular tubes placed in series one after another. The 2D numerical simulation has been solved for different Reynolds number (Re) and the heat transfer coefficient and pressure drops were determined. A custom field function has been written to calculate the entropy generation. The simulation results showed that the Nusselt number and the heat transfer coefficient enhanced with the increase in nanoparticles concentration in nanofluid. From the entropy generation results, it can be predicted that entropy of system increased as concentration of nanoparticles increase. Entropy of the channel with obround tubes was found to be much higher than other geometry of tubes (circular, oval, diamond and rhombus).