Numerical study of natural convection heat transfer in a curve-shaped enclosure with MHD effects and hybrid nanofluids

A computational analysis was performed in a curve-shaped enclosure stuffed with a hybrid \({\text{Fe}}_{3}{\text{O}}_{4}-\text{MWNTs}/{\text{H}}_{2}\text{O})\) nanofluid influenced by a magnetic field. The free convective flow within the chamber is driven by the temperature variation between a cool external curve-shaped enclosure, a heated interior elliptical cylinder, and the upper horizontal wall. The Galerkin finite element method (GFEM) is applied to solve the governing equations, using COMSOL multiphysics as the simulation platform. A quantitative parametric study is conducted for different values of the Hartmann number, nanoparticle volume concentration, Rayleigh number, and varying radii of the interior elliptical cylinder. The findings are presented in terms of the streamlines, temperature contours, and both \({\text{Nu}}_{\text{Local}}\) and \({\text{Nu}}_{\text{avg}}\), taking into account variations in significant physical parameters. The outcomes show that the rate of thermal transport significantly escalates with higher concentrations of the hybrid nanofluid and \(\text{Ra}\); on the other hand, a contrary trend is observed with an increased Hartmann number. Furthermore, the \({\text{Nu}}_{\text{avg}}\) rises with higher values of \(\text{Ra}\) and \(\phi \) but declines as the \(\text{Ha}\) increase. The velocity profile grows by 93.5% as \(\text{Ra}\) increases, but it diminishes by 25.8% with changes in the radius of the inner obstacle.