Mathematical modeling and theoretical investigation of entropy generation in bioconvective micropolar hybrid nanofluid flow with activation energy and Lorentz force

Abstract Hybrid nanofluids (HNFs) have higher thermal conductivity compared to base fluids and single‐component nanofluids. The combination of different types of nanoparticles significantly improves heat conduction, leading to better heat dissipation. By selecting different nanoparticles, thermal conductivity can be tailored for specific applications. In this study, heat transfer and entropy generation (EG) in water‐based bioconvective micropolar hybrid nanofluid flow by stretched cylinder are investigated. The micropolar HNF is developed by uniform mixing of solid nanoparticles of titanium dioxide (TiO 2 ) and silver (Ag). In the formulation of the mathematical model, the impacts of Lorentz force, radiation, Darcy–Forchheimer, fluid friction, binary chemical reaction, surface permeability, and Arrhenius's kinetics are accounted. Boundary layer topographies are implemented to secure the dimensional flow equations. Appropriate transformations are applied to transform the dimensional system into a non‐dimensional one, which is then addressed using the built‐in function (NDSolve) of Mathematica. The dynamics of micropolar HNF velocities (linear and angular), thermal field, Bejan quantity, entropy production, mass concentration, and density of motile microorganisms are studied through graphs. Additionally, skin friction force, heat, mass, and density numbers are numerically analyzed. Results show that the EG is enhanced with rising values of the Brinkman number and thermal radiation variable. It is further noticed that the intensity of the heat transfer rate upsurges with the parameters radiation and curvature, while decaying for improved estimations of Prandtl, Eckert, and Hartmann numbers. Motile density diminishes for higher bioconvection Lewis and Peclet numbers.