Entropy Generation Analysis of EG – Al2O3 Nanofluid Flows through a Helical Pipe

Nanofluids, i.e. fluid suspensions of nanometer-sized solid particles are the new generation of heat transfer fluids for various industrial applications because of their excellent thermal performance. This study analytically and experimentally examines the effects of nanoparticle dispersion on the entropy generation of EG–Al2O3 nanofluid flows through a helical pipe as a heat exchanger under constant wall heat flux thermal boundary condition in laminar regime. It is found that adding nanoparticles improves the thermal performance of EG– Al2O3 flow with Re numbers less than 3700. On the other hand the results shows that adding the 5% by volume Al2O3 nanoparticles in the EG in Dean numbers less than 100 can decrease the entropy generation by 4.511%. Also it is shown that adding nanoparticles leads to increase entropy generation in the cases that fluid flow (pressure drop) irreversibility is dominant. Moreover, optimum conditions of radius ratio and Dean Number for laminar nanofluid flow are obtained.