Entropy-based analysis and economic scrutiny of magneto thermal natural convection enhancement in a nanofluid-filled porous trapezium-shaped cavity having localized baffles

This article presents a modeling approach to predict the thermal natural convection inside a porous trapezium-shaped zone with baffles installed on the adiabatic side-walls. The cavity is filled with nanofluid and exposed under the effect of a magnetic field. The equations which govern the phenomenon have been solved numerically. For various configurations of the installed baffles, temperature field, the flow structure, heat exchange rate, and entropy production have been characterized for sundry figures of parameters i.e. Rayleigh (Ra), Hartmann (Ha), Darcy (Da), material’s porosity (ϵ), and nanoparticles’ concentration (ϕ). In addition, a cost–benefit analysis of the convection enhancement process within the system based on nanomaterials has been proposed. It has been ascertained that rising Ra, Da, and ϵ while lowering Ha improved the convective nanofluid flow. The influence of porous medium properties (material's porosity and permeability) on the convective flow intensity is more effective at moderate Ra. The average cooling rate increases with rising Ra, Da, and ϕ and declining Ha and ϵ. Moreover, obtained results characterize a positive economic feasibility of utilizing nanomaterials to improve thermal natural convection in the presence or absence of a magnetic field.