Vortex generators position effect on heat transfer and nanofluid homogeneity: A numerical investigation and sensitivity analysis

Abstract

A 2-D numerical study and a sensitivity analysis of convective heat transfer in a channel with vortex generators for application in solar heat exchangers are investigated using a Lagrangian-Eulerian model along with determination of the Nanoparticles concentration distribution. Numerical simulations are carried out to study the effects of Reynolds number (50⩽Re⩽250), Nanoparticles volume fraction (0.01⩽Ф⩽0.04), distance between two vortex generators (10mm⩽d⩽20mm) and the angles between them (30°⩽α and β⩽150°) on the heat transfer performance and Nanoparticles distribution. In addition, an analysis on effective parameters is processed utilizing the Response Surface Methodology. The results show a 39.81% increase in the Nusselt number for Re numbers ranged from 150 to 250. Also, it is found that increasing in d and α and reduction of β and Ф increases the mean Nusselt number. Enhancement in d, α and β and also decreasing in Re number and Ф increases the homogeneity of the Nanofluid. Finally, it is shown that the sensitivity of the mean Nusselt number to the Re number, Ф and d parameters is more than the sensitivity of the Nanoparticles concentration ratio to these parameters.