Impact of vortex generator and two-phase MWCNT-MgO/water hybrid nanofluid on thermo-hydraulic performance and exergy and energy efficiency of a solar collector under Kuwait climatic conditions

The effect of curved vortex generators , two-phase MWCNT-MgO/water hybrid nanofluid (HNF) on thermo-hydraulic performance and exergy and energy efficiency of a solar collector in a turbulent flow regime is examined in this study. The simulations performed for the climatic conditions of Kuwait. The two-phase DWCNT-MgO/water HNF is modeled using the mixture model. The numerical study is performed for DWCNT-MgO/water HNF with a volume fraction (9) range of 1-3%, Reynolds number (Re) range of 5000-20,000 , four Pitch Ratio (PR = 0 (Case A), PR = 0.1 (Case B), PR = 0.2 (Case C) and PR = 0.3 (Case D)). It is found that the average Nusselt number (Nuav) and pressure drop (Ap) are enhanced with Re and 9. At 9 = 3% and Re = 20,000, placing the vortex generator with a PR = 0.3 (Case D) inside the solar collector causes the Nuav to improve by 83.09% as compared to the solar collectors without turbulators. In addition, the results demonstrated that the use of vortex generators is desirable in all PRs. For Case D and 9 = 3%, the exergy efficiency is improved by 45.02% as Re is enhanced from 5000 to 20,000.