Radiation and convection heat transfer optimization with MHD analysis of a hybrid nanofluid within a wavy porous enclosure

•GFEM for the evaluation of a wavy porous enclosure with nanofluid is presented.•RSM and Taguchi method is integrated with analytical results to introduce the optimal Nu.•Effects of porosity, radiation and free convection with MHD analysis are presented.•Growing porosity and magnetic force undermine the heat flux and Nu.•Rayleigh number enlargement magnifies natural convection dominance and circulation. Thermal performance maximization is a necessity in various systems that are dealing with any scale of heat flux. This requirement has been intensified due to introduction of more complex and highly crammed products, making heat dissipation a daunting task. Addressing this challenge, a curved porous star-shaped enclosure with a rounded cavity and occupied by hybrid nanoparticles of Fe3O4-Al2O3 scattered uniformly in 1-Hexanol has been simulated by Galerkin finite element method. The temperature difference between inner cavity and outer wavy surface stirred the heat flux within the bounded domain. The determinants of thermal evolution are classified by porosity alteration, radiation intensity, magnetic field and natural convection strength in the form of corresponding dimensionless numbers namely epsilon, Rd, Ha and Ra. The results revealed that 0.01, 99.99 and 0.57 are the optimum values for Ha, Ra and Rd while regarding the porosity, the best output was recognized at ε of 0.1, with radiation having no sizeable impact on the Nu and flow field. Due to contradictory influence of the studies factors, an optimization by RSM and Taguchi incorporation led to the detection of optimum Nu and introduction of an expression for average Nu based on the investigated determinants.