Analysis of Entropy Generation Within Coaxial Cylinder on MHD Free Convective Flow Due to Nonlinear Thermal Radiation in an Isothermal/Isoflux Condition

This study delves into entropy generation analysis within a coaxial cylinder containing an electrically viscous conducting fluid. Both cylinders have porous exteriors and are subjected to heat, with the outer cylinder being cooled. A combination of radial transverse magnetic field and velocity slip is applied. The analysis utilizes the thermal Rosseland diffusion approximation to describe radiative heat flux. The objective is to scrutinize entropy generation and the impact of isothermal and isoflux conditions on heat transfer due to nonlinear thermal radiation in a vertical coaxial cylinder. Steady and unsteady-state solutions are obtained through regular perturbation and implicit finite difference methods, respectively. The results indicate that the Suction parameter reduces fluid velocity, temperature, and skin friction in both the isothermal and isoflux conditions. Magnetic parameters reduce velocity, while Grashop number, injection, and radiation parameters increase velocity and entropy, especially under isothermal conditions. Overall, the results align well with existing literature.