Irreversibility analysis of the flow of a radiative Casson–Williamson hybrid ferrofluid over a moving cylinder

Abstract Entropy generation refers to the energy losses and irreversibilities in the dynamics of non‐linear flow and heat transfer process. Its applications span a wide range, including heat exchangers, turbomachinery, chemical reactors, microfluidic devices, and many others. In this study, we analyze the irreversibility in the heat transfer of a deionized water‐based Casson–Williamson hybrid ferrofluid flowing over a continuously moving cylinder. A magnetic field with non‐changing intensity is exerted transversely to the direction in which the fluid streams. The bivariate spectral local linearization method on multiple overlapping and single grids is used to solve the resulting equations. The results are validated by comparing them with existing studies under certain limiting conditions. Graphical results are presented to show the effects of parametric values, such as the volumetric fraction () of ferrous oxide and aluminum oxide, the Casson () and Williamson () fluid parameters and the thermal radiation () parameter on the fluid velocity, temperature distribution, entropy generation, and Bejan () numbers. Findings indicate that the volumetric fractions of ferrous oxide and aluminum oxide increase the magnitude of the entropy generated in the system.