Entropy generation minimization in bio-convective flow of nanofluid with activation energy and gyrotactic micro-organisms

This article addresses the entropy generation in mixed convection magnetohydrodynamics Eyring–Powell nanofluid flow toward a permeable surface of a cylinder. The flow is modeled considering heat generation and chemical reaction aspects. The influence of buoyancy forces, magnetic field, and thermal radiation is also considered. Moreover, activation energy, viscous dissipation, and permeability effects on bio-nanofluid flow are assimilated in modeling of concentration and energy relations. Total entropy generation is modeled in view of the second thermodynamics law. The governing system of PDEs is deduced by incorporating boundary layer assumptions. Relevant transformations are used to reduce the dimensional flow model into a non-dimensional one. The built-in shooting technique and the NDSolve code in Mathematica software are used to handle the dimensionless flow expressions. Variation in velocity, temperature, concentration, motile micro-organisms, Bejan number, and entropy generation with respect to the involved parameters is scrutinized graphically. Surface drag force, heat transfer rate, mass transfer rate, and density number are further calculated and investigated. Important results are summarized at the end.