Semi-analytical analysis of transport mechanism in hybrid nanomaterial dynamics with oxytactic microbes using Xue model

This study presents a comparative semi-analytical examination of Marangoni-driven mixed convective flow of a hybrid nanofluid containing oxytactic microbes over three different vertical geometries: cone, wedge and plate. The model integrates thermal radiation, viscous dissipation, Dufour-Soret effects, cross-diffusion effects, and magnetohydrodynamics within a single computational framework. The Xue thermal conductivity model characterizes the hybrid nanofluid's thermophysical properties with two different NPs dispersed in the base fluid. Results demonstrate that the Marangoni number significantly enhances velocity profiles and improves both heat and mass transmission rates across all geometries. The plate geometry exhibits superior performance due to uniform surface characteristics compared to the curved cone and wedge surfaces. The magnetic parameter slightly suppresses heat transfer through Lorentz forces. The thermal radiation promotes cooling by reducing thermal boundary layer thickness. Soret and Dufour effects considerably influence concentration and temperature distributions. Microbes' distributions are strongly affected by Peclet number and bioconvection Schmidt numbers for both gyrotactic and oxytactic types. This study provides critical insights for microfluidic bio-devices, thermal management systems, biomedical engineering, and renewable energy technologies requiring controlled transportation of heat, mass, and motile microbes. The velocity profile increases when the Marangoni convection parameter is increased, but the temperature and concentration profiles decrease.