Etude numérique de l’effet des générateurs de vortex longitudinaux sur le transfert thermique d’un écoulement laminaire traversant un micro-canal

Abstract

We conducted, in this work, a three-dimensional numerical study of forced convection heat transfer of a laminar flow of water passing through micro-channels with and without longitudinal vortex generator, using the CFD code “Ansys- Fluent”. This work aimed to elucidate the effect of vortex generators on the dynamic and thermal behavior of the micro-fluidic flow. The results obtained show that the increase in the Reynolds number leads to an improvement in the quality of heat transfer in both cases of the study. Rectangular micro-channel with LVG can improve heat transfer compared to smooth rectangular micro-channel while consuming more pressure drop. In the range of Reynolds numbers between 200 and 1200, a 2-21% increase in the mean Nusselt number was observed for micro-channels with LVG compared to smooth micro-channels. This occurs through better mixing of the fluid, reduction in the thickness of the thermal boundary layer, and increased heat transfer area. In addition, the friction factor has been increased by more than 50% compared to smooth micro-channels, due to the local resistance of LVGs and the presence of secondary flows.