Optimizing heat transfer in circular heat exchanger with hybrid nanofluid using response surface methodology

There has been a lot of research on natural convection, but not much on the effects of magnetic fields, radiation, and hybrid nanofluids in circular spaces. That’s why this study uses advanced computational and statistical methods to improve heat transfer performance. The goal of this study is to look into the sensitivity regarding a free convection in a round cavity with a magnetic field along with radiation effect. This cavity also contains four different shapes of heated obstacles, submerged within a hybrid nanofluid. Sensitivity analysis was performed using response surface methodology (RSM) which is conducted by Minitab software, while computational simulations are conducted using the Galerkin weighted residual method based on Finite Element Method (FEM) by COMSOL Multiphysics. This study examines the impacts of four nondimensional variables: Ra, Rd, Ha, also ϕ_np. An upward trend was identified at the numerical level between the Nu_av with Ra and Rd, although a declining trend is present with Ha. Moreover, Nu_av increases by almost a three and half times (342.53%) when Ra increases from 10³ to 10⁶ and increases 100.80% when Rd parameter increases from 0 to 1. On the other hand, Nu_av decreases by 36.31% while Ha rises 0 to 40. The statistical analysis of the existing model and testing methodologies indicates that the R² values for the response function are elevated. (99.19%), confirming that this model is suitable for evaluating Nu_av. The results of this study will be benefited for the researchers, designers and academicians in the field of thermal energy storage systems, advanced electronic cooling technologies, and design optimization of solar collectors using hybrid nanofluids under MHD and radiation influences.