Hydrothermal scenario of buoyancy-driven magnetized multi-walled carbon nanotube-Fe3O4-water hybrid nanofluid flow within a discretely heated circular chamber fitted with fins

Abstract

This investigation unfolds the hydrothermal changes of magnetized buoyancy-driven multi-walled carbon nanotube (MWCNT)-Fe3O4-water hybrid nanofluidic flow through two centrally placed circular cylinders. Four rectangular T-shaped fins are affixed with the internally placed comparatively small-sized heated cylinder, while the outer cylinder is discretely heated. Four different types of heater-cooler segment arrangements along the outer cylinder periphery are set to execute the investigation. The flow-related leading equations and boundary restrictions are presented and altered to their dimensionless form via suitable similarity transformations. Both nondimensional momentum and energy equations are solved by employing the Galerkin-finite-element technique. Numeric and experimental comparisons are executed to ensure the model’s accuracy. Several streamlines, isotherms, and Nusselt number graphics are revealed to explore the parametric impacts. Results assure accelerated velocity trajectory for Rayleigh numbers, while the flow seems to decelerate for magnetic effect and higher nanoparticle concentrations. Case 1 and Case 3 exhibit higher velocity magnitude and heat transmission out of all four designed cases. Case 1 promotes a 4.68% enhancement in heat transference compared to Case 3 for Rayleigh numbers within the range 104 to 105. Enhanced nanoparticle concentrations assist Case 1 in disclosing 8.13% higher heat transport compared to Case 3. This hydrothermal numeric investigation of natural convective magnetized hybrid nanofluidic inside discretely heated annular chambers might have promising applications in gas turbines, thermal storage devices, heat exchangers, solar receivers, electronic cooling, etc.