Thermohydraulic performance of magnetic nanoparticles via combined upstream and downstream swirl generators in solar heat exchanger tubes

This study summarizes the findings of a numerical examination into heat transfer and fluid flow characteristics of magnetic nanofluid (Fe₃O₄) via an axis-symmetric model of an isothermal circular tube with combined upstream and downstream swirl generators. The effects of combined upstream and downstream swirl generators on heat transfer and fluid flow have been studied. The ANSYS FLUENT 15.0 code is used to run a two-dimensional numerical simulation. The simulation is carried out to gain a better understanding of the physical behavior of thermal and fluid flow in tube fitted with combined upstream and downstream swirl generators under constant wall temperature conditions and Reynolds numbers ranging from 10,000 to 20,000. The heat transfer and thermal performance of swirl generators at varying angles (θ) of 15°, 30°, 45°, and 60° are evaluated and compared to those of a plain circular tube. As the angle and Reynolds number increase, so does the Nusselt number. All swirl generators at different angles (θ = 15°, 30°, 45°, and 60°) show high thermal performance with greater than unity, indicating that the compound heat transfer technique of combined upstream and downstream swirl generators with varying angle is praiseworthy for enhancing heat transmission.