Numerical study of entropy generation of nanofluid flow in helical tube at constant wall temperature

Entropy generation analysis of developing laminar flow through helical coil is performed, numerically. Al2O3/water nanofluid is used as working fluid and numerical simulation using two-phase mixture model with temperature dependent properties is done. Numerical results show a good agreement with experimental data in the literature. The variations of local entropy generation along the tube length is shown for Re=500, 1000, and 1500. The results show that entropy generation enhances while Reynolds numbers increase. Total entropy generation sharply decrease in entrance region and then gradually developed to a constant value for all Reynolds numbers. Entropy generation ratio of nanofluid to water shows that in most length of helical tube, nanofluid make lower entropy production and higher nanoparticle volume fractions cause lower entropy generation.