Thermally stratified non-homogeneous Buongiorno model for unsteady micropolar tetra-hybrid nanofluid flow analysis over howarth’s wavy cylinder with motile microbes

This study examines the unsteady three-dimensional stagnation-point flow of a micropolar tetra-hybrid nanofluid over Howarth’s wavy cylinder in the presence of motile microorganisms and a transverse magnetic field. The tetra-hybrid nanofluid comprises Au−Ag−Cu−TiO2 nanoparticles dispersed in blood and is modeled using a non-homogeneous Buongiorno formulation to account for Brownian motion and thermophoresis effects. The BVP4c technique is skillfully employed to solve flow equations. The results reveal that increasing the magnetic parameter enhances axial and transverse velocities but suppresses microrotation due to magnetic drag effects. The improved micropolar coupling effects result in reduced linear velocities and significantly altered rotational behavior. In addition, improved viscosity of the vortex enhances the microelement’s angular motion. In the absence of the microrotation parameter “m”, microelements adjacent to the wall do not rotate. However, as “m” increases, these elements start to rotate. The thermal analysis reveals that radiation and viscous dissipation effects increase the temperature. In addition, an increase in the Prandtl number results in reduced thickness of the thermal boundary layer. Thermophoresis and Brownian movement effects increase heat transfer rates, while permeability and unsteadiness effects are strong on momentum and microrotation. The mass transfer rate decreases as the bio-convection Lewis number increases. In contrast, it increases as the activation energy increases. The Peclet number decreases the microorganism’s density. The current study reveals an improved heat transfer rate, which increases by about 7.46% compared to previous models.