Investigations of nanofluid flow and heat transfer in a rotating microchannel using single- and two-phase approaches

The impacts of single- (SPM) and two-phase models (TPMs), including Euler-Lagrange (ELM) and Eulerian-Eulerian models (EEM), on a laminar forced convection heat transfer and fluid flow of the Al2O3/water nanofluid are evaluated in a rotating U-shape microchannel with a square cross-section and constant wall temperature. The effects of Reynolds numbers, rotational speed, volume fraction, Brownian motion, and implementation of no-slip and slip conditions are investigated. The slip velocity and heat transfer increase by increasing the volume fraction and rotational speed. The EEM and ELM provide a higher total Nusselt number than the SPM. The maximum heat transfer augmentations of 53.3%, 45.7%, and 41% are achieved for the EEM, ELM, and SPM by increasing the rotational speed from zero to 600 at phi = 5%. The predictions of pressure drop by TPMs are essentially the same but considerably lower than SPM. Unlike the ELM, the nanoparticle concentrations of EEM and SPM are uniform.

Automated summary

This study evaluates the effects of different models on laminar forced convection heat transfer and fluid flow of Al2O3/water nanofluid in a rotating U-shaped microchannel. The results show that increasing the volume fraction and rotational speed can enhance the slip velocity and heat transfer. The Eulerian-Eulerian model and Euler-Lagrange model provide higher total Nusselt numbers compared to the single-phase model. The maximum heat transfer enhancements are achieved by increasing the rotational speed from zero to 600 at a volume fraction of 5%.