Thermosolutal performance of a non-Newtonian Casson fluid in a curvilinear porous baffled chamber with irreversibility and various heating strategies

This study aims to investigate the thermosolutal performance and irreversibility behavior of a non-Newtonian Casson fluid in a curvilinear porous chamber with baffles under various heating strategies. Thermosolutal convection, driven by temperature and solute concentration gradients, plays a critical role in industrial processes such as electronic cooling, thermal storage, and heat exchangers. The novelty of this work lies in the combined use of a Casson fluid and strategically placed baffles within a curvilinear porous enclosure, alongside non-uniform sinusoidal heating applied to the lower boundary, utilizing multifrequency spatial heating profiles for the first time. The inclusion of baffles significantly enhances control over flow structures and heat transfer efficiency. This numerical analysis explores the effects of key parameters, including the Lewis number (1≤Le≤20), the Darcy number (10−4≤Da≤10−2), the Rayleigh number (104≤Ra≤106), and the Casson fluid parameter (0.1≤β≤10), as well as the amplitude, frequency, and offset temperature of the sinusoidal heating. In spite of solving the Navier–Stokes, thermal, and species transport equations using a higher-order compact scheme, the objective is to examine how these parameters influence flow behavior, heat and solute transfer, kinetic energy (K.E.), and entropy generation. The variation in the Casson fluid parameter (β) from 0.1 to 10 leads to significant enhancements in heat transfer, mass transfer, and kinetic energy by 44.01%, 43.85%, and 210.75%, respectively, while simultaneously reducing the total entropy generation by 4.92%.