Grafen-Demir Oksit Hibrit Nanoakışkanı Kullanılan Bir Isı Değiştirici Borusunun Entropi Üretim Analizi

Abstract

In this study, the entropy generation analysis of the Graphene-Iron Oxide-Water hybrid nanofluid with six different volumetric fractions in the range of 0.5-1% in a heat exchanger tube under turbulent flow conditions was numerically investigated. The constant surface heat flux was applied to the tube and the Reynolds number was obtained in the range of 10000-50000. The k − ε RNG solver method was selected for the turbulence method and grid independence was checked. According to the results examining the dimensionless entropy production, entropy production showed a descending trend with the increment of hybrid nanofluid volume fraction. For the dimensionless entropy generation number, which increased with the increasing Reynolds number, configurations above unity were found at the volumetric fractions of 0.5, 0.6, 0.7 and 0.8 %, in addition, all values for entropy generation number with the volume fractions of 0.9 and 1 % were realized below unity up to the Reynolds number of 40000. This result showed that the use Graphene-Iron oxide of hybrid nanofluid in heat exchangers provides great advantages in terms of thermodynamics.