Heat transfer mechanism and irreversibility in power law fluid dynamics through converging/diverging channels with radiative effects

Abstract This study investigates heat transport mechanisms and irreversibility in power law fluid dynamics through converging/diverging channels with radiative effects. Entropy generation (EG) analysis is employed to identify the mechanisms responsible for inefficiencies and irreversibility in the system, which conventional energy analysis cannot capture. The governing flow equations are formulated using the principles of conservation for the Carreau liquid model, while the EG equation is derived based on the second law of thermodynamics. To enhance the originality of the model, a new approach is introduced that incorporates Jaffrey–Hamel flow, alongside the Buongiorno model and viscous heat effects. This model is designed to investigate the flow of thermal radiation within a wedge-shaped channel. This theoretical investigation has practical implications for various industrial processes, including combustion and biofuel production, where minimizing the generation of entropy can enhance efficiency and productivity. The simulation is addressed using the spectral collocation method, facilitated via Mathematica 11.3 software. Our study shows that Nusselt number and Sherwood number significantly decrease as the power law index increases. Velocity distribution decreases as the Weissenberg number increases on a divergent channel. As the Weissenberg number and the power law index increase, the entropy production rate decreases in the divergent section of the channel. A rise in the Eckert number leads to a reduction in the thermal transport rate, indicating that internal friction lowers energy efficiency.