NUMERICAL ANALYSIS OF MHD BIOCONVECTIVE NANOFLUID FLOW OVER A DARCY–FORCHHEIMER POROUS MEDIUM WITH THERMAL RADIATION AND ARRHENIUS ACTIVATION ENERGY EFFECTS

This study analyzes the impact of thermal radiation on the bioconvective flow of a nanofluid over a radially expanding sheet embedded in a Darcy–Forchheimer porous medium. Bioconvection based on gyrotactic microorganisms is crucial for biotechnology and biosensor applications. The primary objective of bioconvection research is to improve energy and mass transmission, which has significant implications for chemical, mechanical, civil, electrical, and process intensification engineering. This work develops a new mathematical model for the unsteady bioconvective flow of a chemically reactive magnetohydrodynamic (MHD) nanofluid with nonlinear thermal radiation and gyrotactic microorganisms in the presence of Darcy–Forchheimer effects. The governing equations include solar radiation, viscous dissipation, and the Buongiorno model in addition to thermophoresis and Brownian motion. A suitable similarity transformation is used to reduce the controlling partial differential equations to a set of ordinary differential equations. The integrated MATLAB solver BVP4C is used to numerically solve these linked higher-order equations for various values of the governing parameters once they have been transformed into a system of first-order ODEs. The results, which are presented graphically, demonstrate significant variations in the motile microbe density, Nusselt number, and skin friction coefficient. It is discovered that increasing the thermophoresis and radiation parameters enhances the fluid temperature, while increasing the Darcy–Forchheimer parameter causes a decrease in wall shear stress.