Conjugate Free Convection in a Thick‐Walled Chamber Filled by Ternary Hybrid Nanofluid Under Magnetic Field

The study investigates entropy generation in a closed domain, driven by natural convective heat transfer and the dynamics of a ternary hybrid nanofluid under the modulation of an external magnetic field. This study is characterized by a geometric configuration where the domain is limited by two vertical walls of varying thicknesses, which introduce a temperature gradient due to differential heating while maintaining the horizontal boundaries thermally insulated. The mathematical representation of this physical scenario is articulated through a set of differential equations, which are solved using the finite element method (FEM). A detailed analysis of entropy generation and average Nusselt number for different fluids has been conducted using graphs and tables for different parameters of interest. It is found that when Ra is small (Ra = 10 3 ), the highest rate of heat transfer (around 9.2%) can be achieved employing ternary fluid as operating fluid rather than base fluid water. This percentage of growth in heat transfer rate with ternary fluid is decreasing with increasing Ra. Particularly, it is low for Ra = 10 5 . The highest percentage of increase in Nusselt number (around 4%) is noticed using a ternary fluid than water in the horizontal direction ( A = 0). On the other hand, the lowest entropy generation is found around (2.48%) in the vertical direction using a ternary fluid rather than water as working fluid.