An investigation on the influence of the shape of the vortex generator on fluid flow and turbulent heat transfer of hybrid nanofluid in a channel

Abstract

The purpose of this study is to numerically investigate flow field and turbulent heat transfer of hybrid nanofluid, water–DWCNT–TiO2 in a two-dimensional rectangular channel with triangular and semicircular vortex generators with three different heights of 1, 2 and 3 mm. For numerically modeling this study, SIMPLEC algorithm was used. Therefore, initially, the geometry of channel and the grid points were generated, and then for solving the mathematical equations via finite volume method, ANSYS Fluent was used. The results indicate that with an increase in Reynolds number and volume fraction (φ) of nanoparticles, the average Nusselt number increases. Also, with an increase in the φ, the pressure loss in the channel increases. About the geometrical shape of the vortex generators, results indicate that with using the semicircular vortex generator, average Nusselt number is higher compared to that of triangular vortex generator. Also, by investigating the performance evaluation criteria of thermal–hydraulic, which is a criterion for comparing the positive effect of the Nusselt number increase with the negative effect of pressure drop, results indicate that this criterion is higher for the semicircular vortex generator.