Odeli J. Kigodi, Nyanga H. Masasila
ABSTRACT The study on Thermodynamic Irreversibility of Steady Viscous Couette Flow with Convective Cooling and Temperature‐Dependent Viscosity reveals that increasing the pressure gradient parameter enhances both temperature and velocity profiles while reducing entropy production, indicating improved thermodynamic efficiency. Similarly, higher Reynolds numbers steepen the thermal and momentum boundary layers with complex patterns in entropy production caused by competing viscous and thermal effects, while increasing viscosity dampens velocity but retains more thermal energy, thereby reducing irreversibilities. Rising Eckert numbers further amplify temperature yet lower entropy production due to viscous dissipation dominance, and higher Prandtl numbers improve heat transfer while reducing entropy production. Conversely, higher Brinkman numbers increase entropy production through intensified viscous dissipation, shifting the irreversibility contribution toward fluid friction, while elevated Biot numbers enhance convective heat transfer but raise entropy production near the boundary. The results show that key parameters markedly influence the coefficient of skin friction () and coefficient of thermal convection (), which regulate thermodynamic irreversibility. While and decrease with little effect on , higher and enhance but reduce , highlighting the coupled roles of frictional and thermal irreversibilities in entropy production. The novelty of this study lies in incorporating temperature‐dependent viscosity with convective cooling in the analysis of entropy production in viscous Couette flow, offering new insights into how simultaneous variations in key flow and thermal parameters govern the balance between frictional and thermal irreversibilities. Overall, the results demonstrate that careful parameter tuning can significantly improve thermal performance and reduce irreversibility in Couette flow systems.