Magnetohydrodynamic Bioconvective Transport of GO–Fe 3 O 4 /CSF Nanofluid in a Rotating Porous Microchannel

This study investigates magnetohydrodynamic rotational flow of a graphene oxide–magnetite (GO–Fe3O4)/cerebrospinal fluid (CSF) hybrid nanofluid in a porous microchannel, motivated by its potential use in magnetically guided intrathecal drug delivery. The model accounts for magnetic-field effects, system rotation, porous resistance, thermal radiation, Brownian motion, thermophoresis, internal heat generation, chemical reaction, and motile microorganism transport. CSF serves as the base fluid, with uniformly dispersed GO and Fe3O4 nanoparticles, and effective hybrid-nanofluid properties are incorporated into the formulation. Appropriate similarity transformations reduce the governing momentum, energy, nanoparticle concentration, and microorganism equations to a coupled nonlinear boundaryvalue problem, which is solved numerically using MATLAB’s bvp4c solver. The numerical investigation characterizes the responses of the velocity, temperature, nanoparticle concentration, and microorganism distributions, together with the skin-friction coefficients and the heat- and mass-transfer rates. The results show that increasing the magnetic parameter from 0 to 3 lowers the primary skin-friction coefficient from 0.7864 to 0.5318. An increase in the rotation parameter from 0 to 6 produces a similar reduction, from 0.8124 to 0.5576. Thermal radiation weakens the wall heat-transfer rate, with the Nusselt number decreasing from 1.3892 to 1.0901 as the radiation parameter rises from 0 to 2. The Sherwood number also declines from 0.9126 to 0.6981 when the thermophoresis parameter increases from 0.1 to 0.7. In contrast, increasing the Schmidt number from 0.5 to 3 raises the Sherwood number from 0.7145 to 1.2187. Moreover, the microorganism density number decreases from 0.9684 to 0.6328 as the Peclet number increases from 0.1 to 1.5. These findings quantify the sensitivity of momentum, thermal, nanoparticle, and microorganism transport to key physical parameters. The model offers a theoretical basis for understanding coupled transport mechanisms in rotating porous microchannels and may inform future mathematical studies of magnetically controlled intrathecal delivery.