Numerical study of hydrodynamic and thermal behavior of Al2O3/Water nanofluid and Al2O3-Cu/Water hybrid nanofluid in a confined impinging slot jet using two-phase mixed model

Abstract

This study utilizes the two-phase mixture model to conduct a numeric study of Al₂O₃/Water and Al₂O₃-Cu/Water (hybrid) nanofluid's hydrodynamic and thermal behavior in a laminar confined impinging slot jet in 50 ≤ Re ≤ 300 and nanoparticles volume fractions (NVF) ranging from 0 - 2%. This study considers various aspect ratios (H/W), including 2, 4, and 6, to investiate the confining effects. This paper gives a comparative analysis of nanofluids and hybrid nanofluids in terms of the parameters concerning the flow: Reynolds and local Nusselt number (Nux), average Nusselt number (Nuavg), flow lines' contour, and temperature distribution under similar geometric conditions and Reynolds number. In comparison with nanofluids, the hybrid nanofluids have higher local Nusselt number on the entire target surface, this advantage of hybrid nanofluid attribute to higher thermal conductivity of them. The average Nusselt numbers of nanofluids and hybrid nanofluids plotted at different Refor various aspect ratios(H/W=2,4), and the effect of aspect ratio and momentum are explained. Furthermore, pumping power of both fluid analysed for all nanoparticles volume fraction (0 - 2%) at different Reynolds number. The result shows that pumping power of hybrid nanofluid is higher than base fluid and nanofluid, because the dynamic viscosity of hybrid nanofluid is higher than base fluid (water) and nanofluid. Besides; the study identified some correlations in the hybrid nanofluids regarding the stagnation point and the average Nusselt numbers. Presumably, these correlations are valid under certain conditions: 50≤ Re ≤ 300, 2 ≤ H/W≤ 6, and volume fracture (0 - 2%).