Comparative analysis of impact of non-linear heat source on mixed convective chemically reacted MHD hybrid nanofluid/nanofluid/fluid over a stretched region

Abstract

This study compares $F{e}_3{O}_4-A{l}_2{O}_3/H_{2}O$ hybrid nanofluid, $A{l}_2{O}_3-H_{2}O$ nanofluid and water, analysing velocity, temperature and concentration profiles. Key parameters include mixed convection, buoyancy ratio forces, space-and-temperature-dependent heat sources, thermophoresis, Brownian motion, Hall current, temperature ratio, magnetic field, rotation parameter, thermal radiation, Schmidt number and chemical reaction. Buongiorno model is applied to explore the model. Similarity transformations reduce the governing partial differential equations (PDEs) to ordinary differential equations (ODEs), solved through MATLAB’s BVP-5C with a shooting method. The analysis reveals that increases in mixed convection and buoyancy enhance the $x$-direction velocity, whereas magnetic and rotational effects lead to its reduction. The velocity along the $y$-axis rises with an increase in the magnetic parameter but declines as the Hall current strengthens. Temperature profile increases with higher values of the space- and temperature-dependent heat source, thermophoresis, Brownian diffusion, rotation parameter, Hall current, thermal radiation and temperature ratio. Concentration is enhanced by thermophoresis but reduced by Brownian diffusion, Schmidt number and chemical reaction effects. The heat transfer rate is enhanced by higher space and temperature dependent heat sources, Brownian motion, thermophoresis and chemical reactions, while it is reduced by increased mixed convection and buoyancy ratios. In contrast, the mass transfer rate increases with all the considered parameters. In the case of velocity distribution, the hybrid nanofluid demonstrates a sharper profile along the $x$-direction under mixed convection, whereas the base fluid displays a stronger variation in this direction when influenced by buoyancy, Hall current and rotational effects. Along the $y$-direction, the velocity profile of the hybrid nanofluid becomes more pronounced with rising magnetic parameter and Hall current. For the temperature distribution, the hybrid nanofluid attains a considerably higher profile than both nanofluid and base fluid when subjected to space- and temperature-dependent heat generation, thermophoretic forces, Brownian diffusion, Hall current, thermal radiation and temperature ratio. Conversely, the base fluid maintains a steeper concentration gradient in response to thermophoresis, Brownian motion, Schmidt number and chemical reaction parameters. Using Karl Pearson's method, the correlation coefficient shows a strong positive relationship (near 1), between the present and past Nusselt number results.