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

Entropy generation analysis of developing laminar flowthrough helical coil is performed, numerically. Al2O3/waternanofluid is used as working fluid and numerical simulationusing two-phase mixture model with temperature dependentproperties is done. Numerical results show a goodagreement with experimental data in the literature. Thevariations of local entropy generation along the tube lengthis shown for Re=500, 1000, and 1500. The results show thatentropy generation enhances while Reynolds numbersincrease. Total entropy generation sharply decrease inentrance region and then gradually developed to a constantvalue for all Reynolds numbers. Entropy generation ratio ofnanofluid to water shows that in most length of helical tube,nanofluid make lower entropy production and highernanoparticle volume fractions cause lower entropygeneration.