Entropy minimization of MHD hybrid nanofluid flow between two concentric cylinders with nonlinear thermal radiation

Nanotechnology’s enormous potential has attracted a lot of interest from a variety of scientific and industrial fields. Among its many uses, nanofluids have shown promise as creative answers to complex heat transfer problems in contemporary engineering systems. The goal of this work is to create a two-dimensional model that takes into account the effects of magnetic fields and nonlinear thermal radiation while analyzing hybrid nanofluid flow within coaxial cylinders. A hybrid nanofluid is created by combining multi-walled carbon nanotubes (MWCNTs) with either copper oxide (CuO) or magnesium oxide (MgO) nanoparticles. This mixture is then suspended in a composite base fluid consisting of ethylene glycol and water. After implementing adequate similarity transformations to non-dimensionalize the governing equations, they are then numerically resolved utilizing MATLAB’s bvp4c solver. By altering the dependent functions’ input parameters, which have a substantial impact on the outcomes, the issue is meticulously investigated. The Nusselt number decreases with increasing Brinkmann number, thermal radiation parameter, and magnetic parameter. Similarly, the skin friction coefficient declines with higher volume fractions of hybrid nanoparticles and stronger magnetic effects, indicating reduced shear stress at the wall due to increased nanoparticle loading and magnetic influence.