A comprehensive study of two-phase flow and heat transfer of water/Ag nanofluid in an elliptical curved minichannel

摘要

In this research,laminar flow and heat transfer of two-phase water/Ag nanofluid with 0–6%volume fraction of nanoparticles at Re=150–700 in a curved geometry are simulated using finite volume method.Studied geometry is an elliptical curved minichannel with curvature angle of 180°.Forced and natural flow of two-phase nanofluid is simulated at Gr=15000,35000 and 75000.For estimation of nanofluid flow behavior,two-phase mixture method is used.The second-order discretization and SIMPLEC algorithm are used for solving governing equations.The results indicate that the increase of volume fraction of nanoparticles leads to the enhancement of the temperature of central line of flow.The increase of Grashof number(Gr^75000)has a great effect on reduction of dimensionless temperature in central line of flow.Creation of thermal boundary layer at Re=500 and after the angle of 30°becomes significant.In low Grashof numbers(Gr^15000),due to the great effects of temperature gradients close to wall,these regions have significant entropy generation.